(2y+9)(8y+5)=0

Solution for (2y+9)(8y+5)=0 equation:

(2y+9)(8y+5)=0

We multiply parentheses ..

(+16y^2+10y+72y+45)=0

We get rid of parentheses

16y^2+10y+72y+45=0

We add all the numbers together, and all the variables

16y^2+82y+45=0

a = 16; b = 82; c = +45;
Δ = b2-4ac
Δ = 822-4·16·45
Δ = 3844
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3844}=62$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(82)-62}{2*16}=\frac{-144}{32}
=-4+1/2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(82)+62}{2*16}=\frac{-20}{32}
=-5/8
$