-7x+8-10x2=7

Solution for -7x+8-10x2=7 equation:

-7x+8-10x^2=7

We move all terms to the left:

-7x+8-10x^2-(7)=0

We add all the numbers together, and all the variables

-10x^2-7x+1=0

a = -10; b = -7; c = +1;
Δ = b2-4ac
Δ = -72-4·(-10)·1
Δ = 89
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-\sqrt{89}}{2*-10}=\frac{7-\sqrt{89}}{-20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{89}}{2*-10}=\frac{7+\sqrt{89}}{-20}
$