Question

In each of the following, determine whether the given values are solution of the given equation or not:
2x² - x + 9 = x² + 4x + 3; x = 2, x = 3

Answer 1

2x² - x + 9 = x² + 4x + 3; x = 2, x = 3
2x² - x + 9 = x² + 4x + 3
2x² - x² - x - 4x + (9 - 3) = 0
x² + 5x + 6 = 0
Now x = 2
L.H.S. = (2)² - 5 x 2 + 6 = 0
10 - 10 = 0 = R.H.S.
∴ x = 2 is a solution of the given equation.
On substituting x = 3 in L.H.S. of equation (1)
⇒ L.H.S. = (3)² - 5 x 3 + 6
⇒ = 15 - 15
= 0
= R.H.S.
∴ x = 3 is a solution of the given equation.