Answer:
a = 0, b = 3
Step-by-step explanation:
3a + b = 3
b = - 3a +3
2a - 5b = - 15
2a - 5(-3a + 3) = - 15
2a + 15a - 15 = - 15
17a = 0
a = 0
b = -3a +3 = - 3 *0 +3 = 3
