SOLUTION: If f(x)=2x^2-x-3 and g(x)=2x-6 find (g-f)(-2)

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Question 1180501: If f(x)=2x^2-x-3 and g(x)=2x-6 find (g-f)(-2)
Found 2 solutions by ikleyn, MathLover1:
Answer by ikleyn(52813) About Me  (Show Source):
You can put this solution on YOUR website!
.

The simplest way is to calculate g(-2) and f(-2), and then take a difference, as prescribed.

With this instruction, you are fully equipped.



Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

If f%28x%29=2x%5E2-x-3+and g%28x%29=2x-6
then
+%28g-f%29%28x%29=2x-6-%282x%5E2-x-3%29
+%28g-f%29%28x%29=2x-6-2x%5E2%2Bx%2B3
+%28g-f%29%28x%29=-2x%5E2%2B2x%2Bx%2B3-6
+%28g-f%29%28x%29=-2x%5E2%2B3x-3
now find
+%28g-f%29%28-2%29
+%28g-f%29%28-2%29=-2%28-2%29%5E2%2B3%28-2%29-3
+%28g-f%29%28-2%29=-2%2A4-6-3
+%28g-f%29%28-2%29=-17