When Lakeesha solved the equation $3(x + 1) = 12$ from problem 6-89, she reasoned this way:
"Since $\it3$ groups of $(x + 1)$ equals $\it3$ groups of $\it4$, then I know that each group of $(x + 1)$ must equal $\it4$."

1. Do you agree with her reasoning? Explain.

   Help (a):

   
   Recall the Equation Mat from problem 6-89.
   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 6-89 will make the equation you wrote in part (b) true.

   Help (c):

   Substitute your answer from problem 6-89 into the equation above and see if the equation is true.