1.5^2+2.5^2=x^2

Solution for 1.5^2+2.5^2=x^2 equation:

1.5^2+2.5^2=x^2

We move all terms to the left:

1.5^2+2.5^2-(x^2)=0

We add all the numbers together, and all the variables

-1x^2+8.5=0

a = -1; b = 0; c = +8.5;
Δ = b2-4ac
Δ = 02-4·(-1)·8.5
Δ = 34
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{34}}{2*-1}=\frac{0-\sqrt{34}}{-2}
=-\frac{\sqrt{}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{34}}{2*-1}=\frac{0+\sqrt{34}}{-2}
=\frac{\sqrt{}}{-2}
$