Answer:
x = 15
Explanation:
The angle is 90 degrees, so 3x qnd 4x - 15 combined would equal 90.
Combining like terms would turn the equation into 7x-15 = 90.
Add 15: 7x = 105
Divide 105 by 7, and x = 15
THESE ARE WRITTEN IN THE CORRECT WAY
Usually 1 referee and 2 referee assistants. Hope this helps!