SOLUTION: This question has proven very tricky, any help would be greatly appreciated. I can solve for x and y on the main problem, but cannot figure this one out. Help please! Let f(x)

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: This question has proven very tricky, any help would be greatly appreciated. I can solve for x and y on the main problem, but cannot figure this one out. Help please! Let f(x)      Log On


   

Question 246231: This question has proven very tricky, any help would be greatly appreciated. I can solve for x and y on the main problem, but cannot figure this one out. Help please!
Let f(x) = x2 - 8x + 16. Find x so that f(x) = 22
Found 3 solutions by dabanfield, scott8148, kensson:
Answer by dabanfield(803) About Me  (Show Source):
You can put this solution on YOUR website!
Let f(x) = x2 - 8x + 16. Find x so that f(x) = 22
If the first term is x2 and not x^2 then:
2x-8x+16 = 22
Then solve for x.
If f(x) = x^2-8x+16 then we have
x^2-8x+16 = 22
x^2-8x-6 = 0
Then solve this quadratic for x.

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
22 = x^2 - 8x + 16

0 = x^2 - 8x - 6 ___ not factorable

use quadratic formula to find x

Answer by kensson(21) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2+-8x+%2B+16+=+22
Subtract 22 from each side
x%5E2+-8x+-6+=+0
This doesn't factorise. Use the formula:
+x+=+%288+%2B-+sqrt%2864+%2B+24%29%29+%2F+2+
+x+=+4+%2B-+sqrt%2822%29+