Question

Brett has a box of colored pencils. He uses 78 pencils and has 120 pencils left in the box. Write an equation showing how many pencils are in the box before he starts drawing.

78 + p = 120
p − 78 = 120
120 + p = 78
p = 120 − 78

Answer 1

p-78=20 is the equation you would use

Answer 2

P=120-78 would be the equation that you use