Question

find the value of k for which x 4 + 10 x3 + 25 x 2 + 15 X + K exactly divisible by X + 7

Answer 1

HEY MATE.....

YOUR ANSWER IS.....

g(x) = x+7=0

So , x = -7

p(x) = x^4+10x^3+25x^2+15x+k = 0

p(-7) = (-7)^4+10(-7)^3+25x^2+15x+k = 0
= 2401+10(-343)+25(49)+15(-7)+k =0
= 2401 - 3430 + 1225-105+k = 0
= 91 + k =0
= 91 = -k

So , k = -91

Hope it helps .....