F(x)=3x/x+7

Solution for F(x)=3x/x+7 equation:

(F)=3F/F+7

We move all terms to the left:

(F)-(3F/F+7)=0


Domain of the equation: F+7)!=0

F∈R


We get rid of parentheses

F-3F/F-7=0

We multiply all the terms by the denominator


F*F-3F-7*F=0

We add all the numbers together, and all the variables

-10F+F*F=0

Wy multiply elements

F^2-10F=0

a = 1; b = -10; c = 0;
Δ = b2-4ac
Δ = -102-4·1·0
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$F_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10}{2*1}=\frac{0}{2}
=0
$
$F_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10}{2*1}=\frac{20}{2}
=10
$