5x^2+7=16x+45x2+7=16x+4

Solution for 5x^2+7=16x+45x2+7=16x+4 equation:

5x^2+7=16x+45x^2+7=16x+4

We move all terms to the left:

5x^2+7-(16x+45x^2+7)=0

We get rid of parentheses

5x^2-45x^2-16x-7+7=0

We add all the numbers together, and all the variables

-40x^2-16x=0

a = -40; b = -16; c = 0;
Δ = b2-4ac
Δ = -162-4·(-40)·0
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-16}{2*-40}=\frac{0}{-80}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+16}{2*-40}=\frac{32}{-80}
=-2/5
$