Question

To solve Lance’s equation, 2(x + 10) = 60, first

A.subtract 10 from both sides
B.multiply both sides by 2
C.divide both sides by 2
D.add 10 to both sides

Then
A.subtract 10 from both sides
B.add 10 to both sides
C.multiply both sides by 2
D.divide both sides by 2

Solve Lance's equation, 2(x + 10) = 60, for x. According to his model, the length of the rectangle is
A. 10 cm
B. 43 cm
C. 15 cm
D. 20 cm

To solve Olivia’s equation, 2x + 20 = 60, first
A.subtract 20 from both sides
B.multiply both sides by 2
C.divide both sides by 2
D.add 20 to both sides

Then
A.multiply both sides by 2
B.add 20 to both sides
C.subtract 20 from both sides
D.divide both sides by 2

Solve Olivia’s equation, 2x + 20 = 60, for x. According to her model, the length of the rectangle is
A. 30 cm
B. 2 cm
C. 20 cm
D. 15 cm

The two equations with different solution steps lead to
A. The same
B. Different

answer(s), because 2(x + 10) = 60 and 2x + 20 = 60
A. Are not
B. Are

equivalent by the distributive property.

Answer 1

divide both sides by 2
subtract 10 from both sides
2(x + 10) = 60
x + 10 = 60/2
x + 10 = 30
x = 30 - 10
x =20

subtract 20 from both sides
divide both sides by 2
2x + 20 = 60
2x = 60 - 20
2x = 40
x = 40/2
x = 20

the same
are