Answer:
4
Step-by-step explanation:
2a+3b=5
2a+3(a-5)=5
2a+3a-15=5
5a=5+15
5a=20
a=4
b = a - 5
_________________________
2a + 3b = 5
2a + 3( a - 5 ) = 5
2a + 3a - 15 = 5
5a - 15 = 5
5a - 15 + 15 = 5 + 15
5a = 20
5a ÷ 5 = 20 ÷ 5
a = 4
_________________________
b = a - 5 ===》 b = 4 - 5 ===》 b = - 1
