SOLUTION: Let f(x)=x^2+6x Evaluate f(2)= Solve f(x)=-9

Algebra ->  Functions -> SOLUTION: Let f(x)=x^2+6x Evaluate f(2)= Solve f(x)=-9      Log On


   

Question 1187303: Let f(x)=x^2+6x
Evaluate f(2)=
Solve f(x)=-9
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Let f%28x%29=x%5E2%2B6x
Evaluate f%282%29=
f%282%29=2%5E2%2B6%2A2
f%282%29=16

Solve f%28x%29=-9
-9=x%5E2%2B6x
0=x%5E2%2B6x%2B9
0=%28x+%2B+3%29%5E2
solutions: x+=+-3 (multiplicity 2, or a double root)