When Lakeesha solved the equation $3(x+1)=12$ from problem 6-54, she reasoned this way:  

“Since $\mathit{3}$ groups of $\mathit{(x+1)}$ equals 3 groups of $\mathit{4}$, then I know that each group of $\mathit{(x+1)}$ must equal $\mathit{4}$.”

1. Do you agree with her reasoning? Explain.

   Hint (a):

   Recall the Equation Mat from problem 6-54.
   Each group of $(x+1)$ corresponds to each group of $4$.

   

   

2. How can the result of Lakeesha’s reasoning be written?

   Answer (b):

   $x+1=4$

3. Verify that your answer from problem 6-54 will make the equation you wrote in part (b) true.

   Hint (c):

   Substitute your answer from problem 6-54 into the equation above and see if the equation is true.