find the cost of each item using total

Question

John and Jose each improved their yards by planting grass sod and geraniums. They bought their supplies from the same sore. John spent $84 on 12ft^2 of grass sod and 5 geraniums. Jose spent $140 on 10 ft^2 of grass sod and 10 geraniums. What is the cost of one ft^2 of grass sod and the cost of one geranium?

Answer 1

Josephina, let's do this. We'll call the cost of grass sod r and the cost of geraniums e.

 

12r + 5e = 84

10r + 10e = 140

 

There are multiple ways to solve this, but let's try elimination. If we multiply the top equation by -2, we'll have -10e, which will cancel out with the 10e in the bottom equation.

 

-24r - 10e = -168

10r + 10e = 140

 

Adding these together, we get -14r = -28, so r = 2.

 

10(2) + 10e = 140

20 + 10e = 140

10e = 120

e = 12

 

So, one square foot of sod is $2 and one geranium is $12.

 

Hope this helps!