(5x+2)(2x-1)=154

Solution for (5x+2)(2x-1)=154 equation:

(5x+2)(2x-1)=154

We move all terms to the left:

(5x+2)(2x-1)-(154)=0

We multiply parentheses ..

(+10x^2-5x+4x-2)-154=0

We get rid of parentheses

10x^2-5x+4x-2-154=0

We add all the numbers together, and all the variables

10x^2-1x-156=0

a = 10; b = -1; c = -156;
Δ = b2-4ac
Δ = -12-4·10·(-156)
Δ = 6241
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6241}=79$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-79}{2*10}=\frac{-78}{20}
=-3+9/10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+79}{2*10}=\frac{80}{20}
=4
$