Question

is x=-1 roots of quadratic equation x2-3x-4=0​

Answer 1

Answer:

X^2-3x-4=0

=>x^2+x-4x-4=0

=>x(x+1)-4(x+1)=0

=>(x+1)(x-4)=0

=>x=-1 & x=4.

Yes x=-1 is a root of the eqn.

Answer 2

Given,

• The quadratic equation $x^2 -3x -4 = 0$ is given.
• x = -1

To find,

• Is x=-1 root of quadratic equation x²-3x-4=0​.

Solution,

Yes, x = -1 is the root of the quadratic equation x²-3x-4=0​.

If x = -1 is a root of the quadratic equation x²-3x-4=0​, then x = -1 must satisfies the given quadratic equation and gives the value 0.

Let us substitute the value of x = -1 in the quadratic equation, we get

       p(x) = x²-3x-4

       p(-1) = (-1)² -3 (-1) -4

               = 1+3 -4

               = 4-4

       p(-1) = 0

⇒ x = -1 is a root of the quadratic equation x²-3x-4=0​.

Hence, yes x = -1 is the root of the quadratic equation x²-3x-4=0​.