Answer:
x = 10
Step-by-step explanation:
To find the value of x that will make the area of both figures to be equal, set the expression for the area of one figure equal to the other.
Thus:
(x + 5)×12 = x × 18
Solve for x
12x + 60 = 18x
Subtract 12x from each side
12x + 60 - 12x = 18x - 12x
60 = 6x
Divide both sides by 6
60/6 = 6x/6
10 = x
x = 10
