3.14*x^2=(78.5)

Solution for 3.14*x^2=(78.5) equation:

3.14x^2=(78.5)

We move all terms to the left:

3.14x^2-((78.5))=0

We add all the numbers together, and all the variables

3.14x^2-78.5=0

a = 3.14; b = 0; c = -78.5;
Δ = b2-4ac
Δ = 02-4·3.14·(-78.5)
Δ = 985.96
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{985.96}}{2*3.14}=\frac{0-\sqrt{985.96}}{6.28}
=-\frac{\sqrt{}}{6.28}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{985.96}}{2*3.14}=\frac{0+\sqrt{985.96}}{6.28}
=\frac{\sqrt{}}{6.28}
$