Question

If x=4 is a zero of the polynomial 2x²+kx-12,then find the value of k.​

Answer 1

$\sf{\pmb{QUESTION:}}$

$\purple {{{\sf If \: x=4 \: is \: a \: zero \: of \: the \: polynomial \: 2x²+kx-12, \: then \: find \: the \: value \: of \: k. }}}$

$\sf{\pmb{ANSWER:}}$

$\pink {{{\sf let \: the \: equation \: be }}} \\ \\ 2 {x}^{2} + kx - 12 \: \purple {{{\sf \: if \: }}} \: x = 4 \\ \\ 2( {4}^{2} ) + k(4) - 12 = 0 \\ \\ 32 + 4k = 12 \\ \\ 32 - 12 = - 4k \\ \\ 20 = - 4k \\ \\ k = \frac{20}{ - 4} \\ \\ \red {{{\sf k = - 5 }}}$