Jonah is planting a rectangular garden the perimeter of the garden is 120 yards and the width is 20 yards what is the length of the garden

P = 2 (L + W)

P = 120

W = 20

120 = 2 (L + 20)

120 = 2L + 40

120 - 40 = 2L

80 = 2L

80/2 = L

40 = L

check ...

120 = 2 (40 + 20)

120 = 2 (60)

120 = 120 (correct)

so the length of the garden (L) = 40 yds