Answer:
a = 4
b = 5
Step-by-step explanation:
In parallelogram, opposite sides are equal and parallel.
therefore 2b + 15 = 5a + b
=> b + 15 = 5a
b = 5a - 15
and 4a + b = 5b - a
=> 5a = 4b
Substitute b = 5a - 15
5a = 4(5a - 15)
5a = 20a - 60
15a = 60
a = 4
b = 5a - 15
b = 5(4) - 15 = 20 - 15 = 5
