Question

If -2 is root of eqyation 3x²+7x+p=0 find the value of k show that the root of equation x²+k(4x+k-1)+p=0 are equal

Answer 1

Answer:

Step-by-step explanation:

Let f(x)=3x²+7x+p

Since -2 is a root of f(x),

f(-2)=0

3(-2)²+7(-2)+p=0

12-14+p=0

P=2

F(x)=3x²+7x+p

X²+k(4x+k—1)+2=0

X²+4kx+k²—k+2=0

∆=16k²—4(k²—k+2)

=16k²—4k²+4k—8

=12k²+4k—8

Two have equal roots

∆=0

12k²+4k—8=0

3k²+k—2=0

3k²+3k—2k—2=0

3k(k+1)—2(k+1)=0

(3k—2)(k+1)=0

K=2/3, k=-1