y=1200/0.8^2

Solution for y=1200/0.8^2 equation:

y=1200/0.8^2

We move all terms to the left:

y-(1200/0.8^2)=0

We get rid of parentheses

y-1200/0.8^2=0

We multiply all the terms by the denominator


y*0.8^2-1200=0

Wy multiply elements

0y^2-1200=0

We add all the numbers together, and all the variables

y^2-1200=0

a = 1; b = 0; c = -1200;
Δ = b2-4ac
Δ = 02-4·1·(-1200)
Δ = 4800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4800}=\sqrt{1600*3}=\sqrt{1600}*\sqrt{3}=40\sqrt{3}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{3}}{2*1}=\frac{0-40\sqrt{3}}{2}
=-\frac{40\sqrt{3}}{2}
=-20\sqrt{3}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{3}}{2*1}=\frac{0+40\sqrt{3}}{2}
=\frac{40\sqrt{3}}{2}
=20\sqrt{3}
$