Hello,
f(x)=2x^3-x^2-4x+9=(((0+2)x-1)x-4)x+9
f(3)=(((0+2)*3-1)*3-4)*3+9=((2*3-1)*3-4)-3+9=(5*3-4)*3+9=11*3+9=33+9=42
or
f(3)=2*3^3-3^2-4*3+9=2*27-9-12+9=54-12=42
15=-4+z/3
+4 +15 = +4 -4 +z/3
cancels the 4 on the right side
19 = z/3
3 x 19 = z/3 x 3
cancels 3 on the right side
I think the answer is z = 57
162
+207
= 369
Okay, so it says he descends 285 feet after he's climbed 369 feet. That means he needs to descend a bit more to reach 453 feet, which we'll just call 0 for now. First, we need to do some subtraction:
369
- 285
= 84
Okay, we know he needs to descend 84 feet to get to his starting point.
So your answer is C
