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Someone please help

f(x) = 2x2 - 5
and
g(x) = 5x + 7
Find
f(g(x)) = [ ? ]x2 +[ ]x + [ ]

User M Karimi
by
2.9k points

1 Answer

4 votes

9514 1404 393

Answer:

f(g(x)) = 50x² +140x +93

Explanation:

Put the function argument in place of x and simplify.

f(g(x)) = f(5x+7) = 2(5x+7)² -5

= 2(25x² +70x +49) -5

f(g(x)) = 50x² +140x +93

_____

We took advantage of the knowledge that ...

(a + b)² = a² +2ab +b² . . . . . where a=5x and b=7

User Irrational
by
3.7k points