Question

For which value of'm'x+3 is the factor of the polynomial x2-2mx+21?

Answer 1

Answer:

for x+3 to be the factor then p(-3) mist be zero

$p( - 3) = 0 \\ { (- 3)}^{2} - 2 \times m \times ( - 3) + 21 = 0 \\ 9 + 6m + 21 = 0 \\ 6m + 30 = 0 \\ 6m = - 30 \\ m = - 5$