Question

If x = -2 is the zero of the polynomial and P(x)= Kx³ + Kx² -8x +4 Find the value of K​

Answer 1

Answer:

• The value of K is 5.

Given:

• x = -2
• p(x) = k×^3 + k×^2 - 8x + 4

To Find:

• The value of k = ?

Solution:

According to the question, value of x is given and in the question we have to put the value of x and we are said to find value of k.

$\: \: \sf \: p(x) = k {x}^{3} + k {x}^{2} - 8x + 4 = 0 \\ \\ \: \: \sf \: p(x) = k \times {( - 2)}^{3} + k \times {( - 2)}^{2} - 8 \times ( - 2) + 4 = 0 \\ \\ \: \: \sf \: p(x) = k \times ( - 8) + k \times 4 + 16 + 4 = 0 \\ \\ \: \: \sf \: p(x) = - 8k + 4k + 16 + 4 = 0 \\ \\ \: \: \sf \: p(x) = - 4k + 16 + 4 = 0 \\ \\ \: \: \sf \: p(x) = - 4k + 20 = 0 \\ \\ \: \: \sf \: p(x) = 20 = 4k \\ \\ \: \: \sf \: p(x) = k = 5$

Hence, the value of k is 5.

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Answer 2

Here is the answer !!