Question

If $f$ and $g$ are real functions defined by $f\left(x\right)=x^2+7$ and $g\left(x\right)=3x+5$ then $f\left(\frac{1}{2}\right)\times g\left(14\right)$ is

• A. $\frac{1336}{5}$
• B. $\frac{1363}{4}$
• C. 1251
• D. 1608

Answer 1

The correct option is B $\frac{1363}{4}$

$f\left(x\right)=x^2+7$

$g\left(x\right)=3x+5$

$f\left(\frac{1}{2}\right)$ = ${\frac{1}{2}}^2+7$

$f\left(\frac{1}{2}\right)$ = $\frac{29}{4}$

$g\left(14\right)$= $3\times 14+5$

$g\left(14\right)$= $47$

$f\left(\frac{1}{2}\right)\times g\left(14\right)$ =$\frac{29}{4}$$\times 47$

= $\frac{1363}{4}$