Question

Gabriella and Stephanie each improved their yards by planting grass sod and ornamental grass. They bought their supplies from the same store. Gabriella spent $172 on 14 ft2 of grass sod and 2 bunches of ornamental grass. Stephanie spent $158 on 7 ft2 of grass sod and 9 bunches of ornamental grass. Find the cost of one ft2 of grass sod and the cost of one bunch of ornamental grass.

Answer 1

14x + 2y = $172
7x + 9y = $158 (x= grass sod y= ornamental grass)

14x + 2y= 172
14x + 18y= 316 (Multiply Equation 2 by 2 to eliminate x)
when you subtract both equations you get -16y= -144 therefore y=9
Final step: Plug in 14x + 2(9) = 172 14x=154 x=11
1 sq ft of grass sod costs $11 and one bunch of ornamental grass costs $9