Question

determine whether values given against the quadratic equation are the roots of equation or not. xsquare +4x-5=0. x=1.-1.

Answer 1

Answer:

putting the value of x =1

4×1-5=0

4-5=0

-1=0

so the values are against the quadratic equation

Answer 2

Answer:

putting x=1,

1+4-5

=0

therefore 1 is a root.

putting x=-1

1-4-5

=-8

therefore -1 is not a root.

The correct roots are:

${x}^{2} + 4x - 5 = 0 \\ by \: splitting \: the \: middle \: term \\ (sum = 4 \\ product = - 5) \\ {x}^{2} + 5x - 1x - 5 = 0 \\ x(x + 5) - 1(x + 5) = 0 \\ (x + 5)(x - 1) = 0 \\ x = - 5 \\x = 1$