I will give brainliest to whoever answers correctly and is first

Answer:
x=16
Step-by-step explanation:
4x+21=85 subtract 21 from both sides
4x=64 divide both sides by 4
x=16
Answer:. x=16°
4x+21=85°. ( parallel anglea are equal)
4x=85-21. (move x-es in one side and known numbers in another side)
4x=64°. (subtract)
x=64/4. (4 is multiplied to x, so when it goes to other side of =, it changes sign and divides )
x=16°