2/5b-8=-1.5b+7

Solution for 2/5b-8=-1.5b+7 equation:

2/5b-8=-1.5b+7

We move all terms to the left:

2/5b-8-(-1.5b+7)=0


Domain of the equation: 5b!=0

b!=0/5

b!=0

b∈R


We get rid of parentheses

2/5b+1.5b-7-8=0

We multiply all the terms by the denominator


(1.5b)*5b-7*5b-8*5b+2=0

We add all the numbers together, and all the variables

(+1.5b)*5b-7*5b-8*5b+2=0

We multiply parentheses

5b^2-7*5b-8*5b+2=0

Wy multiply elements

5b^2-35b-40b+2=0

We add all the numbers together, and all the variables

5b^2-75b+2=0

a = 5; b = -75; c = +2;
Δ = b2-4ac
Δ = -752-4·5·2
Δ = 5585
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{-(-75)-\sqrt{5585}}{2*5}=\frac{75-\sqrt{5585}}{10}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-75)+\sqrt{5585}}{2*5}=\frac{75+\sqrt{5585}}{10}
$