Answer:
x=3 and y=39
Step-by-step explanation:
2y + 3x = 87
y = 6x + 21
2(6x+21) + 3x = 87
12x + 42 + 3x = 87
15x + 42 = 87
15x = 45
x = 3
y = 6(3) + 21
y = 18 + 21
y = 39
