Question

Solve the following quadratic equations using formula.
x² + 3x – 10 = 0

Answer 1

Given: x² + 3x – 10 = 0
On comparing this equation with ax² + bx + c = 0, we get:
a = 1, b = 3, c = –10
For the quadratic equation ax² + bx + c = 0, we know that the quadratic formula is $x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$
On substituting a = 1, b = 3, c = –10, we get:

$x=\frac{-3\pm \sqrt{(3{)}^2-4(1\left)\right(-10)}}{2\left(1\right)}=\frac{-3\pm \sqrt{9+40}}{2}=\frac{-3\pm \sqrt{49}}{2}=\frac{-3\pm 7}{2}=\frac{-3+7}{2},\frac{-3-7}{2}=\frac{4}{2},\frac{-10}{2}=2,-5$

Thus, the solution of the given quadratic equation is x = –5, 2.