Question

What is the value of the rational expression below when x is equal to 4? 12+x/4+x

Answer 1

The expression is equal to 2. 

Let's take the original equation and put 4 in for every x that we see. 

12+x/4+x
12 + (4)/ 4 + (4)
16/8
2

Answer 2

This is easy what you should do is plug in 4 for the x's in the rational expression and what it should look like when finished is: 12+4/4+4.
To remember the steps in which and equation should be solved is:
P=Parentheses
E=Exponents
M=Multiply
D=Division
A=Add
S=Subtract

So the answer to the equation is: 17
Hoped this helped you into solving more equations like this one. :)