Answer: 82.5 - x = R sorry if I am wrong
Step-by-step explanation:
1. We know all the angles in a triangle add up to 180 degrees.
180 = x + x + 15 + R
2. Combine like terms
180 = 2x + 15 + R
3. Subtract 15 from both sides
165 = 2x + R
4. Divide both sides by 2
82.5 = x + R
5. Subtract x from both sides
82.5 - x = R
