8-x=7x2

Solution for 8-x=7x2 equation:

8-x=7x^2

We move all terms to the left:

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

determiningTheFunctionDomain
-7x^2-x+8=0

We add all the numbers together, and all the variables

-7x^2-1x+8=0

a = -7; b = -1; c = +8;
Δ = b2-4ac
Δ = -12-4·(-7)·8
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-15}{2*-7}=\frac{-14}{-14}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+15}{2*-7}=\frac{16}{-14}
=-1+1/7
$