Question

Determine whether the value given against the quadratic equation is the root of the equation.

x2 + 4x − 5 = 0 ; x = 1​

Answer 1

x2

+4x−5=0

given values of x=1,−1

when x=1→1

2

+4(1)−5=1+4−5=0 satisfies the equation.

when x=−1→(−1)

2

+4(−1)−5=1−4−5=−8 does not satisfy the equation.

Therefore x=1 is only the root of given equation.