Question

if one of the zeroes of polynomial 2x²+kx-15 is 3. find the others

Answer 1

other zero is -15/2 ig

Answer 2

f( x) = 2x²+kx-15

given zero of the polynomial is 3

f(3)=2(3)²+3(k)-15=0

18+3k-15=0

3k+3=0

3k=-3

k=-1

Now find the other root
we know sum of zeroes = -b/a =-(-1)/2=1/2

so 3+x=1/2

x=1/2-3

x=-5/2

so other root is -5/2

product of roots =c/a = -15/2

= -5/2*3

=-15/2

hope helped ^!!^^