Please help me find the value of x with all the work

Answer:
x = 21
Step-by-step explanation:
the angles 5x - 35 and 3x + 7 are vertical angles and congruent, thus
5x - 35 = 3x + 7 ( subtract 3x from both sides )
2x - 35 = 7 ( add 35 to both sides )
2x = 42 ( divide both sides by 2 )
x = 21