(4b-2)*(2b+5)=

Solution for (4b-2)*(2b+5)= equation:

(4b-2)(2b+5)=

We move all terms to the left:

(4b-2)(2b+5)-()=0

We add all the numbers together, and all the variables

(4b-2)(2b+5)=0

We multiply parentheses ..

(+8b^2+20b-4b-10)=0

We get rid of parentheses

8b^2+20b-4b-10=0

We add all the numbers together, and all the variables

8b^2+16b-10=0

a = 8; b = 16; c = -10;
Δ = b2-4ac
Δ = 162-4·8·(-10)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-24}{2*8}=\frac{-40}{16}
=-2+1/2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+24}{2*8}=\frac{8}{16}
=1/2
$