Question

what number should be added to the polynomial X square + 7 x minus 35 so that 3 is a zero of the polynomial

Answer 1

$f(x) = {x}^{2} + 7x - 35 + k \\ f(3) = 0 \\ 9 + 21 - 35 + k = 0 \\ k = 5$

Answer 2

Pls see the pic...
Answer is in the pic...