.75x2=7+1/3x

Solution for .75x2=7+1/3x equation:

.75x^2=7+1/3x

We move all terms to the left:

.75x^2-(7+1/3x)=0


Domain of the equation: 3x)!=0

x!=0/1

x!=0

x∈R


We add all the numbers together, and all the variables

.75x^2-(1/3x+7)=0

We get rid of parentheses

.75x^2-1/3x-7=0

We multiply all the terms by the denominator


(.75x^2)*3x-7*3x-1=0

We multiply parentheses

3x^2-7*3x-1=0

Wy multiply elements

3x^2-21x-1=0

a = 3; b = -21; c = -1;
Δ = b2-4ac
Δ = -212-4·3·(-1)
Δ = 453
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{-(-21)-\sqrt{453}}{2*3}=\frac{21-\sqrt{453}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+\sqrt{453}}{2*3}=\frac{21+\sqrt{453}}{6}
$