Question

I just don't know how to indicate values on ration equations

Answer 1

Solving the equation we have:

`\begin{gathered} (x+3)/(x-3)=(12)/(3) \\ (x+3)/(x-3)=4\text{ (Simplifying the fraction)} \\ x+3=4(x-3)\text{ (Multiplying x-3 on both sides of the equation)} \\ x+3=4x-12\text{ (Distributing)} \\ x+3+12=4x\text{ (Adding 12 to both sides of the equation)} \\ 3+12=4x-x\text{ (Subtracting x from both sides of the equation)} \\ 15=3x\text{ (Adding)} \\ (15)/(3)=x\text{ (Dividing by 3 on both sides of the equation)} \\ 5=x\text{ } \end{gathered}`

The solution is x=5 and it is valid as the result of replacing it in the denominator is not zero. ( 5 - 3 ≠ 0)