3x+(8x*5x)=1015

Solution for 3x+(8x*5x)=1015 equation:

3x+(8x*5x)=1015

We move all terms to the left:

3x+(8x*5x)-(1015)=0

We add all the numbers together, and all the variables

3x+(+8x*5x)-1015=0

We get rid of parentheses

3x+8x*5x-1015=0

Wy multiply elements

40x^2+3x-1015=0

a = 40; b = 3; c = -1015;
Δ = b2-4ac
Δ = 32-4·40·(-1015)
Δ = 162409
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{162409}=403$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-403}{2*40}=\frac{-406}{80}
=-5+3/40
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+403}{2*40}=\frac{400}{80}
=5
$