Question

if -5 is a root of the equation 2x2 + px - 15 = 0 and the quadratic equation p(x2 + x) + k = 0 has equal roots than find k.

Answer 1

Answer:

k=7/4

Step-by-step explanation:

x=-5

2x^2+px-15=0

2(-5)^2+p(-5)-15=0

2×25-5p-15=0

50-5p-15=0

35=5p

7=p

p=7

p(x^2+x)+k=0

7(x^2+x)+k=0

7x^2+7x+k=0

If roots are equal delta =0

a=7, b=7, c=k

Delta=b^2-4ac

0=7^2-4×7×k

0=49-28k

28k=49

k=49/28

k=7/4

HOPE THIS BRING A SMILE IN YOUR FACE