12.6-2(7.2-y)=4.9y(6-y)

Solution for 12.6-2(7.2-y)=4.9y(6-y) equation:

12.6-2(7.2-y)=4.9y(6-y)

We move all terms to the left:

12.6-2(7.2-y)-(4.9y(6-y))=0

We add all the numbers together, and all the variables

-2(-1y+7.2)-(4.9y(-1y+6))+12.6=0

We multiply parentheses

2y-(4.9y(-1y+6))-14.4+12.6=0


We calculate terms in parentheses: -(4.9y(-1y+6)), so:

4.9y(-1y+6)

We multiply parentheses

-4y^2+24y

Back to the equation:

-(-4y^2+24y)


We add all the numbers together, and all the variables

-(-4y^2+24y)+2y-1.8=0

We get rid of parentheses

4y^2-24y+2y-1.8=0

We add all the numbers together, and all the variables

4y^2-22y-1.8=0

a = 4; b = -22; c = -1.8;
Δ = b2-4ac
Δ = -222-4·4·(-1.8)
Δ = 512.8
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-22)-\sqrt{512.8}}{2*4}=\frac{22-\sqrt{512.8}}{8}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-22)+\sqrt{512.8}}{2*4}=\frac{22+\sqrt{512.8}}{8}
$