Answer:
see explanation
Step-by-step explanation:
17
The diagonals of a parallelogram bisect each other, then
x + 6 = 11 ( subtract 6 from both sides )
x = 5
and
y - 7 = 10 ( add 7 to both sides )
y = 17
(18)
The opposite sides of a parallelogram are congruent , then
3a + 11 = a + 15 ( subtract a from both sides )
2a + 11 = 15 ( subtract 11 from both sides )
2a = 4 ( divide both sides by 2 )
a = 2
and
3b + 5 = b + 11 ( subtract b from both sides )
2b + 5 = 11 ( subtract 5 from both sides )
2b = 6 ( divide both sides by 2 )
b = 3
