2Remember:1. A variable is a letter used to represent an unknown value.2. A numerical expression includes numbers and operations.3. An algebraic expression contains variables, numbers and operations.
3x a b y Variables are letters that represent unknown values. How did I What do I represent?How did Iget here?What am I?xaI am so unknownbyVariables are letters that represent unknown values.
4Numerical Expressions Numerical expressions include numbers and operation symbols.
5n Algebraic Expressions An algebraic expression includes: Numbers Operationsand Variablesn
6Let’s look at examples of a numerical expressions: 3287(4)
7Let’s look at examples of algebraic expressions. 2
8Algebraic expressions like phrases in English are incomplete. EquationsAlgebraic expressions like phrases in English are incomplete.An equation, like a sentence, is complete. You will notice theinclusion of a very special symbol.An equation is made up of numbers, variables,and an equal sign.3b + 5 = 26
9Rewrite these verbal expressions as algebraic expressions. 1. the sum of s and 12s+122. the product of 15 and some number15n3. n to the seventh powern74. 56 increased by twice a number56+2a5. Four less than a numbern-4
10Let’s write equations for these sentences. 1. Forty-three less than n is equal to 35.n – 43 = 352. Seven more than y is 13.y + 7 = 13