Question

How do you solve `30x^2-5x=60`?

Answer 1

`x=3/2,`
`x=-4/3`

Explanation:

The contributor below solved it by factoring, here I'll solve it using my favourite method for quadratic equations : The Quadratic Formula.

So, like the contributor above, divide the entire equation by 5.
`6x^2-x=12`
Subtract 12 from both sides.
`6x^2-x-12`
Here is where we deviate from the factoring method : We take `a=6, b=-1, c=-12`
And substitute it into the quadratic formula which is : `(-b+-sqrt(b^2-4ac))/(2a)`
You'll get :
`(-(-1)+-sqrt((-1)^2-4*6*-12))/(2*6)`
Simplify
`(1+sqrt(1+288))/12`

`(1+sqrt(289))/12`

`1/12+sqrt(289)/12, 1/12-sqrt(289)/12`

`1/12+17/12, 1/12-17/12`

`18/12, -16/12`

`3/2, -4/3`