Answer:
x=5
Step-by-step explanation:
We know that a triangle consists of 180°. So to start, you take the two given angles and add them together. 48+90=138.
Now you subtract the 138 from the total of 180 to get the degrees of the remaining angle. 180-138=42°.
Now set the unknown angle equal to 42. (5x+17) = 42
Subtract 17from both sides to get 5x=25
Divide 5 from both sides to get x=5