7=0.02x^2

Solution for 7=0.02x^2 equation:

7=0.02x^2

We move all terms to the left:

7-(0.02x^2)=0

We get rid of parentheses

-0.02x^2+7=0

a = -0.02; b = 0; c = +7;
Δ = b2-4ac
Δ = 02-4·(-0.02)·7
Δ = 0.56
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{0.56}}{2*-0.02}=\frac{0-\sqrt{0.56}}{-0.04}
=-\frac{\sqrt{}}{-0.04}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{0.56}}{2*-0.02}=\frac{0+\sqrt{0.56}}{-0.04}
=\frac{\sqrt{}}{-0.04}
$