18=-0.07x^2+49

Solution for 18=-0.07x^2+49 equation:

18=-0.07x^2+49

We move all terms to the left:

18-(-0.07x^2+49)=0

We get rid of parentheses

0.07x^2-49+18=0

We add all the numbers together, and all the variables

0.07x^2-31=0

a = 0.07; b = 0; c = -31;
Δ = b2-4ac
Δ = 02-4·0.07·(-31)
Δ = 8.68
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{8.68}}{2*0.07}=\frac{0-\sqrt{8.68}}{0.14}
=-\frac{\sqrt{}}{0.14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{8.68}}{2*0.07}=\frac{0+\sqrt{8.68}}{0.14}
=\frac{\sqrt{}}{0.14}
$