(X+7)(2x+5)=0

Solution for (X+7)(2x+5)=0 equation:

(X+7)(2X+5)=0

We multiply parentheses ..

(+2X^2+5X+14X+35)=0

We get rid of parentheses

2X^2+5X+14X+35=0

We add all the numbers together, and all the variables

2X^2+19X+35=0

a = 2; b = 19; c = +35;
Δ = b2-4ac
Δ = 192-4·2·35
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-9}{2*2}=\frac{-28}{4}
=-7
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+9}{2*2}=\frac{-10}{4}
=-2+1/2
$