This is the only concept I have learned how to do so far with function notation in Algebra l.
f(x) = 4x + 11
f(5) = 4(5) + 11
f(5) = 20 + 11
f(5) = 31
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g(x) = -6x + 13
g(5) = -6(5) + 13
g(5) = -30 + 13
g(5) = -17
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I don't know how to solve your particular question, but I think that it wants you to multiply f by g and then multiply that solution by 5.