Answer:
4 months
Step-by-step explanation:
to get them similar, you have to set them equal to each other.
y=15x+20, y=40+10x.
15x+20=40+10x
5x=20
x=4 months
Answer A
as taught to us till now
B
When x=1, we will use the second equation
-(1)+1 = 0