(2.5x^2+10)=225

Solution for (2.5x^2+10)=225 equation:

(2.5x^2+10)=225

We move all terms to the left:

(2.5x^2+10)-(225)=0

We get rid of parentheses

2.5x^2+10-225=0

We add all the numbers together, and all the variables

2.5x^2-215=0

a = 2.5; b = 0; c = -215;
Δ = b2-4ac
Δ = 02-4·2.5·(-215)
Δ = 2150
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:

$\sqrt{\Delta}=\sqrt{2150}=\sqrt{25*86}=\sqrt{25}*\sqrt{86}=5\sqrt{86}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-5\sqrt{86}}{2*2.5}=\frac{0-5\sqrt{86}}{5}
=-\frac{5\sqrt{86}}{5}
=-\sqrt{86}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+5\sqrt{86}}{2*2.5}=\frac{0+5\sqrt{86}}{5}
=\frac{5\sqrt{86}}{5}
=\sqrt{86}
$