Question

How do you solve `5x^2 - 7x - 3 = 0` using the quadratic formula?

Answer 1

`x=(7+sqrt109)/10` or `(7-sqrt109)/10`

Explanation:

Quadratic formula gives the solution of `ax^2+bx+c=0` as `x=(-b+-sqrt(b^2-4ac))/(2a)`

As in `5x^2-7x-3=0`, `a=5`, `b=-7` and `c=-3`

`x=(-(-7)+-sqrt((-7)^2-4*5*(-3)))/(2*5)`

= `(7+-sqrt(49+60))/10`

i.e. `x=(7+sqrt109)/10` or `(7-sqrt109)/10`