(-20*21+87*11/2)b=-200+187

Solution for (-20*21+87*11/2)b=-200+187 equation:

(-20*21+87*11/2)b=-200+187

We move all terms to the left:

(-20*21+87*11/2)b-(-200+187)=0


Domain of the equation: 2)b!=0

b!=0/1

b!=0

b∈R


We add all the numbers together, and all the variables

(87*11/2-420)b-(-13)=0

We add all the numbers together, and all the variables

(87*11/2-420)b+13=0

We multiply parentheses

957b^2-420b+13=0

a = 957; b = -420; c = +13;
Δ = b2-4ac
Δ = -4202-4·957·13
Δ = 126636
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{126636}=\sqrt{4*31659}=\sqrt{4}*\sqrt{31659}=2\sqrt{31659}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-420)-2\sqrt{31659}}{2*957}=\frac{420-2\sqrt{31659}}{1914}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-420)+2\sqrt{31659}}{2*957}=\frac{420+2\sqrt{31659}}{1914}
$