Answer:
x =15
Step-by-step explanation:
The area of a triangle is given by
A = 1/2 bh
We know the area=225 and the base= (45-x) and the height =15
Substituting these into the equation
225 = 1/2 (45-x)*15
225 = 15/2 (45-x)
Multiply each side by 2/15
2/15 *225 = 2/15*15/2 (45-x)
30 = 45-x
Subtract 45 from each side
30-45 =45-x-45
-15 = -x
Multiply each side by -1
15=x