You set the expressions equal to each other since they are congruent, then solve.
5x + 24 = 9x - 17
First subtract 24 from both sides to get
5x = 9x - 41
The subtract 9x from both sides to get
-4x = -41
Then divide both sides by -4 to get
x = 41/4 or as a decimal x = 10.25