Finding the length using perimeter and equations

Question

When two sides of a square are increased by 7 cm and the other two sides are decreased by 4 cm ,the new perimeter is 70 cm .what is the original perimeter of the square

Answer 1

A square has equal sides x

Length = x + 7

Width = x - 4

Perimeter = 2L + 2W

70 = 2(x + 7) + 2 (x - 4)

70 = 2x + 14 + 2x - 8

70 = 4x + 6

70 - 6 = 4x

64 = 4x

x = 16

Since the square has equal sides x = 16, then the perimeter is 16 x 4 = 64 cm

Check:

70 = 2(16 + 7) + 2(16 - 4)

70 = 2(23) + 2(12)

70 = 46 + 24

70 = 70