widest to narrowest: y=3/2x2, y= -1/2x2, y= 1/4x2
A=10*8+((8-6)(15-10))/2
A=10*8+(2*5)/2
A=10*8+10/2
A=10*8+5
A=80+5
A=85 feet
Therefore the answer is D
Hope this helps :)
Consider this solution, if it is possible, check the result:
1) if to divide polynomial 'x³-3x²-6x+8' on 'x+2' result is: x²-5x+4, then x³-3x²-6x+8=(x+2)(x²-5x+4);
2) x²-5x+4=(x-1)(x-4), then
3) x³-3x²-6x+8=(x+2)(x-1)(x-4).
4) zeros are: -2;1;4. Other zeros are: 1 and 4.
Answer: 1;4.