Answer:
21) x = 0
23) x = 7
Step-by-step explanation:
In a parallelogram, the opposite sides are congruent. Using this fact, we can create equations for both problems.
21)
[tex]2x + 18 = 18[/tex]
Subtract 18.
[tex]2x = 0[/tex]
Divide by 2.
[tex]x = 0[/tex]
23)
[tex]2x - 3 = 11[/tex]
Add 3.
[tex]2x = 14[/tex]
Divide by 2.
[tex]x = 7[/tex]
