Question

For what value of k is the polynomial f of X is equals to 3 x ki power 4 - 4 x cube + x square + 5 x + k

Answer 1

${x}^{4} - {4x}^{3 }+ {x}^{2} + 5x + k \\ f(3) = {3}^{4} - 4 \times {3}^{3} + {3}^{2} + 5(3) + k \\ f(3) = 81 - 108 + 9 + 15 + k \\ f(3) = 105 - 108 + k \\ - 3 + k \\ k = 3$