10x2*5=21

Solution for 10x2*5=21 equation:

10x^2*5=21

We move all terms to the left:

10x^2*5-(21)=0

Wy multiply elements

50x^2-21=0

a = 50; b = 0; c = -21;
Δ = b2-4ac
Δ = 02-4·50·(-21)
Δ = 4200
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:

$\sqrt{\Delta}=\sqrt{4200}=\sqrt{100*42}=\sqrt{100}*\sqrt{42}=10\sqrt{42}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-10\sqrt{42}}{2*50}=\frac{0-10\sqrt{42}}{100}
=-\frac{10\sqrt{42}}{100}
=-\frac{\sqrt{42}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+10\sqrt{42}}{2*50}=\frac{0+10\sqrt{42}}{100}
=\frac{10\sqrt{42}}{100}
=\frac{\sqrt{42}}{10}
$