Answer: x = 30
Step-by-step explanation: Since the triangles are similar, you can begin to compare the sides and notice the trend that each side of the triangle on the right, is just a side of the left triangle multiplied by 6.
Here's the best way to show your work on the paper:
5x = 30
x = 30/5
x = 6
4x = 24
x = 24/6
x = 6
5 * 6 = 30