Question

The value of p if px⁴ + 7x² – 18 is divisible by (x – 3)

A) 9/5

B)  -5/9

C)  5/9

D) 1

Answer 1

Correct option is (B) -5/9

\(\because\) \(px^4+7x^2-18\) is divisible by (x - 3).

\(\therefore\) When \((px^4-7x^2-18)\) is divided by (x - 3), it leaves remainder 0.

\(\therefore\) \(p(3)^4+7\times3^2-18=0\)

\(\Rightarrow\) 81p + 63 - 18 = 0

\(\Rightarrow\) 81p = -63 + 18

\(\Rightarrow\) 81p = -45

\(\Rightarrow\) \(p=\frac{-45}{81}=\frac{-5}{9}\)

Answer 2

Correct option is  B) -5/9