 #  1. -5 + 1  2. 3 + -7  3. - 4a + 8a. Objective: To add and subtract real numbers using rules.

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 1. -5 + 1  2. 3 + -7  3. - 4a + 8a

Objective: To add and subtract real numbers using rules.

 If both number (a and b) are positive then just add the numbers and keep the positive sign.  a + b = ∣a∣+∣b∣ Ex: 6 + 8 = 14  If both number (a and b) are negative then just add the numbers and keep the negative sign.  a - b = -( ∣a∣+∣b∣) Ex: -6 + (-8) = -14

 If a is positive and b is negative take the difference of the two and then the sign of the number with the greater absolute value.  a + b = ∣a∣-∣b∣ a has a greater value or  a + b = - ( ∣b∣-∣a∣) b has the greater value Ex: 9 + (-4) = 9-4 = 5 3 + (-7) = -(7-3) = -4  If a and b are opposites, then a + b = 0

 -11 + (-10) + 10 + 9 =  3x + [2 + (-3x)] + -22=

 Definition of Subtraction – For all real numbers a and b, the difference a-b is defined by a-b = a +(-b) (To subtract- turn the problem into an addition problem with the opposite of the second number b.) Example: -6 – (-10) = - 6 + 10 = 4

 9 -12 =  3 – (-4) =

 P55 # 1-6 all  P61 # 1-15 odd

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