If f(x) = x^2 + 1 and g(x) = 3x + 1, find g(20) + f(6).

Question

solomonzelman · Answer

$$f(x)=x^2+1~~~~~~~~~and~~~~~~~~~~~g(x)=3x+1$$
plug in 6 for x into
$$x^2+1$$
to find f(6).
and plug in 20 for x into $$3x+1$$ to find g(20)
add the new functions that you come up with, and there will be your answer.

solomonzelman · Answer

$$f(6)=\color{blue} {     6    } ^2+1~~~~~~~~->~~~~~~~~~f(6)=37$$
$$g(20)=3 \times \color{blue} {     20    } +1~~~~~~~~~->~~~~~~~~~g(20)=61$$

anonymous · Answer

98?

solomonzelman · Answer

$$g(20)+f(6)$$ is the same as adding what they are equal to.
$$\color{red} {   61+37    } $$

so YES, 98 is correct!

anonymous · Answer

So to solve an f(x) equation in that form I just input and then add the solutions?

anonymous · Answer

Also, does that mean f and g have no value?

solomonzelman · Answer

Yes, f and g have no value.
(to say g=...) wouldn't make sense of course)

anonymous · Answer

Got it, Thank you.

solomonzelman · Answer

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