b=3*(-7/9)+5

Solution for b=3*(-7/9)+5 equation:

b=3(-7/9)+5

We move all terms to the left:

b-(3(-7/9)+5)=0

We multiply all the terms by the denominator


b*9)+5)-(3(-7=0

Wy multiply elements

9b^2-7=0

a = 9; b = 0; c = -7;
Δ = b2-4ac
Δ = 02-4·9·(-7)
Δ = 252
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:

$\sqrt{\Delta}=\sqrt{252}=\sqrt{36*7}=\sqrt{36}*\sqrt{7}=6\sqrt{7}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-6\sqrt{7}}{2*9}=\frac{0-6\sqrt{7}}{18}
=-\frac{6\sqrt{7}}{18}
=-\frac{\sqrt{7}}{3}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+6\sqrt{7}}{2*9}=\frac{0+6\sqrt{7}}{18}
=\frac{6\sqrt{7}}{18}
=\frac{\sqrt{7}}{3}
$