5: x = 5 6: x = 2
Explanation:
Problem 5:
Since parallelogram ABCD has to be a parallelogram, than that means that all opposite sides have to be congruent on it. One side has to be equivalent to the opposite side, so the equation on that line is equivalent to the equation on the opposite side, as well. EXAMPLE: 5x = 3x+10, which turns to 2x = 10, which turns to x = 5.
Problem 6:
Just like Problem 5, the opposite lines in the middle of the rhombus have to be congruent to one another since the given shape must be a parallelogram. So 4x = 8, and that turns to x = 2. I solved all of these problems using multi-step equations.
Hope this helped!