90 - x = 4x
4x + x = 90
5x = 90
x = 90/5
x = 18
Answer:
8 ft
Step-by-step explanation:
The area (A) of a triangle = 
bh
where b is the base and h the perpendicular height
Using b = 20 and h = 12, then
A = 0.5 × 20 × 12 = 120 ft²
Using b = 30 and perpendicular height = h, then
0.5 × 30 × h = 120
15h = 120 ( divide both sides by 15
h = 8
When one side of a quadrilateral is not to be fenced (ex. a river, as in this case), the optimal fencing to maximize the area is always to use half the fencing for the length, and one-fourth for each of the two widths
A) For 1000 ft of fencing which is to be used to cover 1 length and 2 widths:
L = 1000/2 = 500, and W = 1000/4 = 250. The optimal dimensions will be 250 x 500 ft.
B) This will result in an area of 250*500 = 125,000 sq. ft.
I just know that the answer is not f(x) by itself. I don't know if it's f(x) with g(x). Or not enough information
