Presentation on theme: "Chapter 1 Tools of Algebra In Chapter 1, You Will… Review and extend your knowledge of algebraic expressions and your skills in solving equations and."— Presentation transcript:
Chapter 1 Tools of Algebra
In Chapter 1, You Will… Review and extend your knowledge of algebraic expressions and your skills in solving equations and inequalities. Solve absolute value equations and inequalities by changing them to compound equations and inequalities.
1-1 Properties of Real Numbers What Youll Learn … To graph and order real numbers To identify and use properties of real numbers
Number Classification Natural numbers are the counting numbers. 1,2,3,4,….. Whole numbers are natural numbers and zero. 0,1,2,3,4,…. Integers are whole numbers and their opposites. ….-3,-2,-1,0,1,2,3,…. Rational numbers can be written as a fraction. 7/5, -3/2, 0, 0.3, -1.2, 9 Irrational numbers cannot be written as a fraction. 2, 7, All of these numbers are real numbers.
Example 1: Real World Connection Many mathematical relationships involving variables are related to amusement parks. Which set of numbers best describes the values for each variable? a.The cost C of admission for n people b.The maximum speed s in meters per second on a roller coaster of height h in meters c.The parks profit (or loss) P in dollars for each week w of the year
Example 2: Graphing Numbers on a Number Line Change to Decimals
Example 3: Ordering Real Numbers An inequality is a mathematical sentence that compares the value of two expressions using an inequality symbol. < Less than < Less than or equal to > Greater than > Greater than or equal to Compare and
The opposite or additive inverse of any number a is –a. The sum of opposites is 0. Find the opposite of a.-3.2 b.400 c.1/5 The reciprocal or multiplicative inverse of any nonzero number a is 1/a. The product of reciprocals is 1. Find reciprocal of a.-3.2 b.400 c.1/5 Example 4: Finding Inverses
Properties of Real Numbers PropertyAdditionMultiplication Closure a +b is a real numberab is a real number Commutativea + b = b + a ab = ba Associative (a+b)+c = a+(b+c) ( ab)c = a(bc) Identitya+0=a, 0+a=aa(1)=a, 1(a)=a Inversea +(-a) = 1a(1/a)= 1, a 0 a(b+c) = ab+acDistributive
Example 5: Identify Properties of Real Numbers Which property is illustrated? a.6+(-6) = 0 b.(-4 1) - 2 = -4 – 2 c.(3+0) - 5 = 3 – 5 d.-5 + [2 +(-3)] = (-5 + 2) + (-3) *
Example 6: Finding Absolute Value The absolute value of a real number is its distance from zero on the number line. Find the absolute value of: a. -4 b. 0 c. -1 (-2)
1-2 Algebraic Expressions 1.03 Operate with algebraic expressions (polynomial, rational, complex fractions) to solve problems. What youll learn … To evaluate algebraic expressions To simplify algebraic expressions
Evaluating Algebraic Expressions A variable is a symbol, usually a letter, that represents one or more numbers. An expression that contains one or more variables is an algebraic expression or a variable expression. When you substitute numbers for the variables in an expression and follow the order of operations, you evaluate the expression.
Example 1- Evaluating an Algebraic Expression For x = 4 and y = -2 x + y ÷ x 3x – 4y + x – y x + 2x ÷ y - 2y Example 2- Evaluating an Algebraic Expression with Exponents For c = -3 and d = 5 c 2 - d 2 c(3 – d) – c 2 -d 2 - 4(d – 2c)
Example 3 Real World Connection The expression -3y +61 models the percent of eligible voters who voted in presidential elections from 1960 to In the expression, y represents the number of years since Find the approximate percent of eligible voters who voted in 1988.
Simplifying Algebraic Expressions In an algebraic expression such as -4x +10, the parts that are added are called terms. A term is a number, a variable, or the product of a number and one or more variables. The numerical factor in a term is the coefficient. Like terms have the same variables raised to the same powers.
Example 4 Combining Like Terms 3k - k 5z 2 – 10z – 8z 2 + z -(m – n) +2(m – 3n) y(1 + y)- 3y 2 – (y + 1)
Example 5 Finding Perimeter 3x 2x – y y 5x – 2y 2x 3c 2d 3c d d 6c – 2d 8c +d
1-3 Solving Equations 1.03 Operate with algebraic expressions (polynomial, rational, complex fractions) to solve problems. What youll learn … To solve equations To solve problems by writing equations
Solving Equations An equations that contains a variable may be true for some replacements of the variable and false for others. A number that makes the equation true is a solution of the equation.
Properties of Equality Reflexive Property a = a Symmetric Property If a=b then b=a Transitive Property If a=b and b=c then a=c Addition Property If a=b then a+c = b+c Subtraction Property If a=b then a-c = b-c Multiplication Property If a=b then ac = bc Division Property If a=b and c0 then a/c = b/c Substitution Property If a=b then b can be substituted for a in any expression to obtain an equivalent expression.
Steps to Solving Equations Simplify each side of the equation, if needed, by distributing or combining like terms. Move variables to one side of the equation by using the opposite operation of addition or subtraction. Isolate the variable by applying the opposite operation to each side. First, use the opposite operation of addition or subtraction. Second, use the opposite operation of multiplication or division. Check your answer.
Example 1 Solving an Equation with a Variable on Both Sides 13y + 48 = 8y - 472t – 3 = 9 – 4t
Example 2 Using the Distributive Property 3x – 7(2x – 13) = 3(-2x +9) 6(t – 2) = 2(9 – 2t)
Example 3 Solving a Formula for One of Its Variables Solve for h. A = ½ h (b 1 + b 2 ) Solve for x. ax +bx – 15 = 0 Example 4 Solving an Equation for One of Its Variables
Example 5 Real World Connection A dog kennel owner has 100 ft of fencing to enclose a rectangular dog run. She wants it to be 5 times as long as it is wide. Find the dimensions of the dog run.
Example 6 Using Ratios The lengths of the sides of a triangle are in the ratio 3:4:5. The perimeter of the triangle is 18 in. Find the lengths of the sides. The lengths of the sides of a triangle are in the ratio 12:13:15. The perimeter of the triangle is 120 cm. Find the lengths of the sides.
Example 7 Real World Connection Radar detected an unidentified plane 5000 mi away, approaching at 700 mi/h. Fifteen minutes later an interceptor plane was dispatched, traveling at 800 mi/h. How long did the interceptor take to reach the approaching plane?
1-4 Solving Inequalities 1.03 Operate with algebraic expressions (polynomial, rational, complex fractions) to solve problems. What youll learn … To solve and graph inequalities To solve and write compound inequalities
Properties of Inequalities Let a, b and c represent real numbers. Transitive Property If ab and bc, then ac. Addition Property If ab, then a+c b+c. Subtraction Property If ab, then a-c b-c. Multiplication Property If ab and c>0, then ac bc. If ab and c<0, then ac bc. Division Property If ab and c>0, then a/c b/c. If ab and c<0, then a/c b/c.
Solving Inequalities To solve an inequality, use the same procedure as solving an equation with one exception. When multiplying or dividing by a negative number, reverse the direction of the inequality sign. To graph the solution set, circle the boundary and shade according to the inequality. Use an open circle for and closed circles for or.
Example 1 Solving and Graphing Inequalities 3x – 12 < (2 - x) 41
Example 2 No Solutions or All Real Numbers as Solutions 2x – 3 > 2(x – 5)4(x – 3)+ 7 4x + 1
Real World Connection The band shown at the left agrees to play for $200 plus 25% of the ticket sales. Find the ticket sales needed for the band to receive at least $500
Compound Inequalities A compound inequality is a pair of inequalities that are joined by the words and or or.
Example 4 Compound Inequality Containing And 3x -1 > -28 and 2x +7 < 19 2x >x +6 and x -7 2
Example 4 Compound Inequality Containing Or 4y or 3y X – 1 8
Real World Connection The plans for a gear assembly specify a length of cm with a tolerance of cm. A machinist finds that the part is now cm long. By how much should the machinist decrease the length?
1-5 Absolute Value Equations and Inequalities 2.08 Use equations and inequalities with absolute value to model and solve problems; justify results. a) Solve using tables, graphs, and algebraic properties.
Objective 1: Absolute Value Equations The absolute value of a number is its distance from 0 on a number line and distance is nonnegative
Example 1 Solving Absolute Value Equations 2y – 4 = 123x + 2 = 12
Example 2 Solving Multi-Step Absolute Value Equations 3 4w – = x = 33
Example 3 Checking for Extraneous Solutions 2x + 5 = 3x + 4 x = x - 1 An extraneous solution is an answer that is NOT a solution
Example 4 Solving Inequalities of the form A b 3x x – 3 > 7
Properties Let k represent a positive real number. x k is equivalent to x -k or x k. x k is equivalent to -k x k.
Example 5 Solving Inequalities of the form A < b 3 2x < 15 5z < 34
Real World Connection The specifications for the circumference C in inches of a basketball for men is 29.5 C 30. Write the specification as an absolute value inequality.
In Chapter 1, You Should Have Reviewed and extended your knowledge of algebraic expressions and your skills in solving equations and inequalities. Solved absolute value equations and inequalities by changing them to compound equations and inequalities.