Question

if m and n are roots of the quadratic equation x2+zx+8=0 with condition m-n=0 then the value of z is _______ a)+/-8 b)+/-6 c)+/-5 d)+/-7​

Answer 1

Answer:

x

2

−5x+3=0

a=1,b=−5,c=3

m+n=

a

−b

=

1

−(−5)

=5

m+n=

a

c

=

1

3

=3

Answer 2

Answer:

±8

Step-by-step explanation:

given that m and n are the roots of this quadratic equation.

also , given that difference of the roots is zero.

that implies that both roots are equal. if both roots are equal the discriminant will be zero.

so,

b²- 4ac = 0

=> z²- 4.2.8 = 0

=> z² = 8.8

=> z² = 64

=> z = √64

=> z = ±8.