You want to put a 5 inch thick layer of topsoil for a new 23 ft by 18 ft garden. the dirt store sells by the cubic yards. how many cubic yards will you need to order? the store only sells in increments of 1/4 cubic yards.

5 inches = 5/12 = 0.4166 feet

23 x 18 x 0.4166 = 172.5 cubic feet

1 cubic foot = 0.037037 cubic yards

172.5 x 0.037037 = 6.39 round up to 6.5 cubic yards

1) solve for x by multiplying each equation with the opposite number and making one a negative

-4(5x + 2y =-9)-4
5(4x +3y = 25)5

2) multiply on both sides of equal sign

-20x - 8y = 36
20x + 15y = 125

3) add all the like terms to get new equation

7y = 161

4) simplify

7y = 161
/7 /7

y = 23

5) make ordered pair and then input 23 into original equation

( x , 23)

5x + 2y = -9
5x + 2(23) = -9
5x + 46 = -9
-46 -46
5x = -55
/5 /5

x = -11

6) input to ordered pair

(-11, 23)

7) Thats your answer!