Question

p(x)=3x²+2x-k find the value of k if is x is 4​

Answer 1

Step-by-step explanation:

$p(x) = 3 {x}^{2} + 2x - k \\ if \: x = 4 \\p(4) = 0 \\ p(4) = 3 \times {4}^{2} + 2 \times 4 - k = 0 \\ 3 \times 16 + 2 \times 4 - k = 0 \\ 48 + 8 - k = 0 \\ 56 - k = 0 \\ k = 56$

hence the value of k is 56