40-9y(y=2)

Solution for 40-9y(y=2) equation:

40-9y(y=2)

We move all terms to the left:

40-9y(y-(2))=0

We multiply parentheses

-9y^2+18y+40=0

a = -9; b = 18; c = +40;
Δ = b2-4ac
Δ = 182-4·(-9)·40
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-42}{2*-9}=\frac{-60}{-18}
=3+1/3
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+42}{2*-9}=\frac{24}{-18}
=-1+1/3
$