(1x+7)(8x+2)=0

Solution for (1x+7)(8x+2)=0 equation:

(1x+7)(8x+2)=0

We add all the numbers together, and all the variables

(x+7)(8x+2)=0

We multiply parentheses ..

(+8x^2+2x+56x+14)=0

We get rid of parentheses

8x^2+2x+56x+14=0

We add all the numbers together, and all the variables

8x^2+58x+14=0

a = 8; b = 58; c = +14;
Δ = b2-4ac
Δ = 582-4·8·14
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(58)-54}{2*8}=\frac{-112}{16}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(58)+54}{2*8}=\frac{-4}{16}
=-1/4
$