Scenario: You have a hill in your backyard that needs to be cut in half for a retaining wall. You want the retaining wall to extend from the hillside 2 feet, so you can plan a garden using the upper space. You want this garden to be at a height of 2 feet.
 The hill is 3 feet tall at the top, and the sloping distance of the hillside from the top to the bottom is 5 feet.
 The width of the fence line is 100 feet.
 The fence line is 62 feet from the back of the house.
 Where, in the hill, should you start digging to remove the dirt and place the retaining wall?
 Choose the type of brick to use. Brick A: measures 12x2x3 inches and costs $1.29 per brick. Brick B: measures 12x2x6 and costs $2.38 per brick.
also Draw a diagram to illustrate the problem of the retaining wall.

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.

step-by-step explanation:

what is the figure? attach a picture.