Question

Find (f - g)(x)

f(x) = 3x2 – 2x
g(x) = 9x2 - X+7

A. -6x2 - x-7
B. 6x2 – x+7
C. 12x2 - x-7
D. -6x2 – 3x-7
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Answer 1

$\sf \huge \blue{option : \: ( \: a \: ) }$

$\sf f(x) = {3x}^{2} - 2x \\ \sf g(x) = {9x}^{2} - x + 7$

$\sf \pink{find : (f - g)(x) } \\ \sf {3x}^{2} - 2x - ( {9x}^{2} - x + 7) \\ \sf = {3x}^{2} - 2x - {9x}^{2} + x - 7 \\ \sf = {3x}^{2} - {9x}^{2} - 2x + x - 7 \\ \sf = - {6x}^{2} - x - 7$

Answer 2

Answer:

(A) 6x²-x-7

Step-by-step explanation:

We have the two functions:

$f(x)=3x^2-2x\text{ and } g(x)=9x^2-x+7$

And we want to find:

$(f-g)(x)$

This is equivalent to:

$=f(x)-g(x)$

Hence, by substitution:

$=(3x^2-2x)-(9x^2-x+7)$

Distribute:

$=(3x^2-2x)+(-9x^2+x-7)$

Rearrange:

$=(3x^2-9x^2)+(-2x+x)+(-7)$

Combine like terms:

$=-6x^2-x-7$

Hence, our answer is A.