x2*2.5=7

Solution for x2*2.5=7 equation:

x2*2.5=7

We move all terms to the left:

x2*2.5-(7)=0

Wy multiply elements

2.5x^2-7=0

a = 2.5; b = 0; c = -7;
Δ = b2-4ac
Δ = 02-4·2.5·(-7)
Δ = 70
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{70}}{2*2.5}=\frac{0-\sqrt{70}}{5}
=-\frac{\sqrt{}}{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{70}}{2*2.5}=\frac{0+\sqrt{70}}{5}
=\frac{\sqrt{}}{5}
$