5x(x-2)=2(x+7)

Solution for 5x(x-2)=2(x+7) equation:

5x(x-2)=2(x+7)

We move all terms to the left:

5x(x-2)-(2(x+7))=0

We multiply parentheses

5x^2-10x-(2(x+7))=0


We calculate terms in parentheses: -(2(x+7)), so:

2(x+7)

We multiply parentheses

2x+14

Back to the equation:

-(2x+14)


We get rid of parentheses

5x^2-10x-2x-14=0

We add all the numbers together, and all the variables

5x^2-12x-14=0

a = 5; b = -12; c = -14;
Δ = b2-4ac
Δ = -122-4·5·(-14)
Δ = 424
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{424}=\sqrt{4*106}=\sqrt{4}*\sqrt{106}=2\sqrt{106}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-2\sqrt{106}}{2*5}=\frac{12-2\sqrt{106}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+2\sqrt{106}}{2*5}=\frac{12+2\sqrt{106}}{10}
$