17.5=(b)(b+2)

Solution for 17.5=(b)(b+2) equation:

17.5=(b)(b+2)

We move all terms to the left:

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


We calculate terms in parentheses: -(b(b+2)), so:

b(b+2)

We multiply parentheses

b^2+2b

Back to the equation:

-(b^2+2b)


We get rid of parentheses

-b^2-2b+17.5=0

We add all the numbers together, and all the variables

-1b^2-2b+17.5=0

a = -1; b = -2; c = +17.5;
Δ = b2-4ac
Δ = -22-4·(-1)·17.5
Δ = 74
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{-(-2)-\sqrt{74}}{2*-1}=\frac{2-\sqrt{74}}{-2}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{74}}{2*-1}=\frac{2+\sqrt{74}}{-2}
$