Question

if x = 3/2 is a zero of polynomial 2x^2+ kx - 12, find the value of k.​

Answer 1

Step-by-step explanation:

$2 {x}^{2} + kx - 12 =0 \\ 2( { \frac{3}{2} })^{2} + k \times \frac{3}{2} - 12 = 0 \\ 2 \times \frac{9}{4} + \frac{3}{2} k - 12 = 0 \\ \frac{9}{2} + \frac{3}{2}k - 12 = 0 \\ \frac{3}{2}k = 12 - \frac{9}{2} \\ \frac{3}{2} k = \frac{24 - 9}{2} \\ \frac{3}{2} k = \frac{15}{2} \\ k = \frac{15 \times 2}{2 \times 3} \\ k = 5$