-60=5x^2-7(4x+3)

Solution for -60=5x^2-7(4x+3) equation:

-60=5x^2-7(4x+3)

We move all terms to the left:

-60-(5x^2-7(4x+3))=0


We calculate terms in parentheses: -(5x^2-7(4x+3)), so:

5x^2-7(4x+3)

We multiply parentheses

5x^2-28x-21

Back to the equation:

-(5x^2-28x-21)


We get rid of parentheses

-5x^2+28x+21-60=0

We add all the numbers together, and all the variables

-5x^2+28x-39=0

a = -5; b = 28; c = -39;
Δ = b2-4ac
Δ = 282-4·(-5)·(-39)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-2}{2*-5}=\frac{-30}{-10}
=+3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+2}{2*-5}=\frac{-26}{-10}
=2+3/5
$