Question

Let f(x) = $x^2$ and g(x) = 3x + 4 . Find the value of $\frac{(f+g)\left(x\right)}{(f-g)\left(x\right)}$ when x = 1

• A. 4/3
• B. 3/4
• C. -4/3
• D. -3/4

Answer 1

The correct option is C

-4/3

( f + g) (x) = f(x) + g(x) = $x^2$ + 3x + 4

( f - g) (x) = f(x) - g(x) = $x^2$ - 3x - 4

To find $\frac{(f+g)\left(x\right)}{(f-g)\left(x\right)}$ at x = 1 , put x = 1

$\Rightarrow$ $\frac{1+3+4}{1-3-4}=\frac{8}{-6}=\frac{-4}{3}$