Question

if a and b are zeros of polynomial Kx²+4x+4 find the value of k such that (a+b)²+2ab=24​

Answer 1

Answer:

a+b=-4/k and a×b=4/k

now, (a+b)²+2ab=24

or, (-4/k)²+2×4/k=24

or, 16/k²+8/k=24

or, (16+8k)/k²=24

or, 16+8k=24k²

or, 24k²-8k-16=0

or, 8(3k²-k-2)=0

or, 3k²-k-2=0

or, 3k²-3k+2k-2=0

or, 3k(k-1)+2(k-1)=0

or, (k-1)(3k+2)=0

either, k-1=0; or, k=1

or, 3k+2=0; or, k=-2/3