please help, due today

Answer:
Answer: 3) x=11; 4) x=35.
Step-by-step explanation:
1) the opposite sides of a parallelogram are equal
2) the opposite angles of a parallelogram are equal, and the sum of adjacent angles = 180 degrees
3) the diagonals of the parallelogram intersect and are divided in half by the point of intersection
respectively for problem number 3:
7x+1=8x-10
11=х
for problem number 4:
2x+5+3x=180
5х=175
х=35
Answer: 3) x=11; 4) x=35.