Answer:
f(-9) = 619
Explanation:
To solve for f(-9), plug -9 in for x in the equation of f(x). In other words, change all x's into -9 in the equation 7 - 5x + 7x² and then solve.
f(x) = 7 - 5x + 7x²
Plug in -9 for x.
f(-9) = 7 - 5(-9) + 7(-9)²
Simplify. 5(-9) = -45, 7(-9)² = 7(81) = 567
f(-9) = 7 + 45 + 567
Solve.
f(-9) = 619
The answer is 619.
I hope this helps. If you need clarifications of anything, feel free to ask. Happy studying. :)