Solving Addition and Subtraction Equations

What equation does the model represent?

• 4+ 1 = 7

• 4x = 7

• x - 4 = - 7

• x + 4 =7

Write the equation represented by the scale diagram

Solve for x

Solve for x.

x - 7 = 2

y + 6 = 3

• y = - 3

• y = 0

• y = 9

• y = -18

x + (-18) = 34

Mathematical Equivalence

ON

x - 7 = -15

Mathematical Equivalence

ON

In order to solve 6j - 9 = 27, I would first ​ (a)   , then ​ (b)   .

• add 9 to both sides

• subtract 9 from both sides

• divide by 9 on both sides

• divide both sides by 6

• subtract 6 from both sides

• add 6 to both sides

Solve the equation.

x + 9 = -5

Mathematical Equivalence

OFF

Solve for m.

8 = m - 3