5x^2-22x=(-21)

Solution for 5x^2-22x=(-21) equation:

5x^2-22x=(-21)

We move all terms to the left:

5x^2-22x-((-21))=0

We add all the numbers together, and all the variables

5x^2-22x+21=0

a = 5; b = -22; c = +21;
Δ = b2-4ac
Δ = -222-4·5·21
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-22)-8}{2*5}=\frac{14}{10}
=1+2/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22)+8}{2*5}=\frac{30}{10}
=3
$