Question

If k+y is factor of y^2+y-15 and y^3+a find k and a

Answer 1

y + K is a factor of f ( y) then by factor theorem f(k) =0

f(y) = y² + y - 15

f(k) = 0

k² +K -15 = 0

K = (-1 ± √61)/ 2

g(y) = y³ + a

g(k) = 0

k³ + a = 0

a = - k³ =- {(-1 ±√61)/2}^3