Question

(ii) 3x2 + 8x-k = 0; x = -5​

Answer 1

Hello mate....✔✔✔

Given....

$x = - 5$

and

$3x {}^{2} + 8x - k = 0$

take the "x" value in equation......

then》

$3( - 5) {}^{2} + 8( - 5) - k = 0$

3(25)-40-K = 0

75-40-K = 0

K = 75-40

K = 30

Hope it helps you....✔✔✔

Answer 2

$\huge\underline{Answer:-}$

$\bf{The \:Value \: of \:k \:is 35 }$

$\boxed{Given:-}$

$\bf{3x² + 8x - k = 0}$

where, $\bf{X = -5}$

$\underline{Solution:-}$

$\color{black}{3x² + 8x - k = 0}$

Now, putting the value of x in the Above Equation , we get-

⇒$\color{black}{3( -5)² + 8( -5) - k = 0}$

⇒$\color{black}{3 × 25 + ( -40) - k = 0}$

⇒$\color{black}{75 - 40 -k = 0}$

⇒$\color{black}{35 - k = 0}$

⇒$\color{black}{-k = -35}$

⇒$\color{black}{K= 35}$

$\therefore{K = 35}$