Answer:
20. x = 5, y = -2
21. x = 11, y = 12
22. x = 22, y = 11
23. x = 11, y = 10
Step-by-step explanation:
20. Opposite sides in the parallelogram are congruent, so
Solve this system of two equations:
Multiply the first equation by 2 and add two equations:
Substitute it into the first equation:
21. Opposite angles in the parallelogram are congruent, so
Consecutive angles are supplementary, so
Solve this system of two equations:
From the second equation
Substitute it into the first equation:
22. Opposite angles in the parallelogram are congruent, so
Consecutive angles are supplementary, so
Solve this system of two equations:
From the first equation
Substitute it into the second equation:
23. Opposite sides in the parallelogram are congruent, so
Solve this system of two equations:
Multiply the second equation by 2 and subtract it from the first equation:
Substitute it into the first equation: