Question

Find the value of x.

Answer 1

Since both sides are the same, you'd set the two expressions equal to one another. 

3x - 5 = 2x + 1
x - 5 = 1
x = 6

So, the value of x is 6.

Answer 2

The triangles are congruent by SAS.
The sides measuring 3x - 5 and 2x + 1 are congruent by CPCTC.

3x - 5 = 2x + 1

3x = 2x + 6

x = 6