490=b+(2*b)2

Solution for 490=b+(2*b)2 equation:

490=b+(2b)2

We move all terms to the left:

490-(b+(2b)2)=0

We add all the numbers together, and all the variables

-(+b+2b^2)+490=0

We get rid of parentheses

-2b^2-b+490=0

We add all the numbers together, and all the variables

-2b^2-1b+490=0

a = -2; b = -1; c = +490;
Δ = b2-4ac
Δ = -12-4·(-2)·490
Δ = 3921
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{3921}}{2*-2}=\frac{1-\sqrt{3921}}{-4}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{3921}}{2*-2}=\frac{1+\sqrt{3921}}{-4}
$