(2a+1)(3-a)=0

Solution for (2a+1)(3-a)=0 equation:

(2a+1)(3-a)=0

We add all the numbers together, and all the variables

(2a+1)(-1a+3)=0

We multiply parentheses ..

(-2a^2+6a-1a+3)=0

We get rid of parentheses

-2a^2+6a-1a+3=0

We add all the numbers together, and all the variables

-2a^2+5a+3=0

a = -2; b = 5; c = +3;
Δ = b2-4ac
Δ = 52-4·(-2)·3
Δ = 49
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{49}=7$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-7}{2*-2}=\frac{-12}{-4}
=+3
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+7}{2*-2}=\frac{2}{-4}
=-1/2
$