Addition
What operation is the inverse operation of addition?
(think opposite -- think undo)
subtraction
What operation is the inverse operation of subtraction?
(think opposite -- think undo)
addition
What operation is the inverse operation of multiplication?
(think opposite -- think undo)
division
What operation is the inverse operation of division?
(think opposite -- think undo)
multiplication
Anytime you see a number directly next to a variable (letter) this indicates WHICH operation?
multiplication
13 = x + 7
6 = x
or
x = 6
y - 1 = 11
y = 12
24 = 6m
x = 4
m/2 = 12
m = 24
Justin had 14 pieces of gum. Mark gave him more. Justin now has 108 pieces of gum. Let m represent the number of pieces of gum. How many pieces of gum did Mark give Justin?
94 pieces [of gum]
y + 21 = -21
y = - 42
-9 + m = -10
m = -1
45 = 9m
m = 5
x / -14 = -84
x = 6
Myra gave Lizzy $21. Lizzy now has a total of $48. How much money did Lizzy have to start? Let x represent the amount of money.
x = $27
x + (-10) = 30
x = 40
m - 106 = 3
m = 109
-165= -11m
m = 15
y/8 = -64
y = -8
Gavin bought 7 games from Brody. Gavin spent a total of $63. How much did each video game cost? Let c represent the cost of each game.
c = $9
14 + m = 90
m = 76
-20 = m - (-16)
m = -36
-1/2 x = 3
x = -6
m/-9 = 81
m = -729
Myra brought cookies to school and shared them with 8 people. Each of the 8 people got to choose 3 cookies. Let x represent the total number of cookies. How many cookies did Myra bring to school?
x = 24 cookies