Answer:
x = 20
Step-by-step explanation:
The sum of the two angles is 90 degrees
x+3x+10 = 90
Combine like terms
4x+10 = 90
Subtract 10 from each side
4x+10-10 = 90-10
4x= 80
Divide each side by 4
4x/4 = 80/4
x and 3x + 10 form a right angle, then
x + 3x + 10 = 90
4x + 10 = 90 ( subtract 10 from both sides )
4x = 80 ( divide both sides by 4 )
