0.8x-8=9/25x+3

Solution for 0.8x-8=9/25x+3 equation:

0.8x-8=9/25x+3

We move all terms to the left:

0.8x-8-(9/25x+3)=0


Domain of the equation: 25x+3)!=0

x∈R


We get rid of parentheses

0.8x-9/25x-3-8=0

We multiply all the terms by the denominator


(0.8x)*25x-3*25x-8*25x-9=0

We add all the numbers together, and all the variables

(+0.8x)*25x-3*25x-8*25x-9=0

We multiply parentheses

0x^2-3*25x-8*25x-9=0

Wy multiply elements

0x^2-75x-200x-9=0

We add all the numbers together, and all the variables

x^2-275x-9=0

a = 1; b = -275; c = -9;
Δ = b2-4ac
Δ = -2752-4·1·(-9)
Δ = 75661
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-275)-\sqrt{75661}}{2*1}=\frac{275-\sqrt{75661}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-275)+\sqrt{75661}}{2*1}=\frac{275+\sqrt{75661}}{2}
$