Question

The difference between the values of the polynomial $3x^3–2x+5$ at x = 2 and x = 1 is

• A. 25
• B. 19
• C. 33
• D. 21

Answer 1

The correct option is B 19

Let $f\left(x\right)=3x^3–2x+5$
$\therefore f\left(2\right)=3(2{)}^3–2(2)+5$
$=24–4+5$
$=24+1=25$
Also, $f\left(1\right)=3(1{)}^3–2(1)+5$
$=3–2+5=6$
$\therefore f\left(2\right)–f\left(1\right)=25–6=19$
Hence, the correct answer is option (2).