Sumalee and Willie each improved their yards by planting grass sod and geraniums. They bought their supplies from the same store.

Question

Sumalee spent $69 on 4 ft2 of grass sod and 3 geraniums.
Willie spent $71 on 3 ft2 of grass sod and 4 geraniums. What is the cost of one ft2 of grass sod
and the cost of one geranium?

Answer 1

So what we need to do is create a set of equations. Lets start by IDing our variables.

Let s = grass sod and g = germaniums.

Here's what we know:

4s + 3g = 69 (4 sections of grass and 3 germaniums costs $69)

3s + 4g = 71 (3 sections of grass and 4 germaniums costs $71)

 

We can solve this problem by using the elimination method. We can multiply the first equation by -3 and the second by 4:

-12s - 9g = -207

12s + 16g = 284

------------------------

7g = 77

 

Divide both sides by 7:

g = 11

 

From here, you can plug in the value of the germaniums into either/both of the equations to find the cost of grass sod.