marking brainliest to whoever gives me the correct answer and i good explanation!

Answer:
Step-by-step explanation:
The triangle should equal 180 degrees. You already have 84+60= 144
Take that 144 with the equation of the other angle. 144-180 is 36
5x+1=36 subtract 1 from both sides
5x=35 divide by 5
x=7
check:
36 + 84+60= 180