Given that the first three terms of the arithmetic sequence are A-1, a + 1 and a + 3, what is the general term formula of the sequence?

Given that the first three terms of the arithmetic sequence are A-1, a + 1 and a + 3, what is the general term formula of the sequence?

2n+a-3

Given that the first three terms of the arithmetic sequence {an} are A-1, a + 2, 2A + 3, then the general term formula of this sequence is?

A1=a-1
A2=a+2
A3=2a+3
D=(A3-A1)/(3-1)=A-1=(A2-A1)/(2-1)=3
So d = 3 A1 = 2 an = 2 + (n-1) 3 = 3n-1

If the first three terms of the arithmetic sequence {an} are A1, 2a and A3 respectively, then the general term formula of the sequence is
If the first three terms of the arithmetic sequence {an} are A1, 2a and a + 3 respectively, then the general term formula of the sequence is
If the first three terms of the arithmetic sequence {an} are a + 1, 2a, and a + 3 respectively, then the general term formula of the sequence is? It's not clear just now. Look at this

2A - (a + 1) = a + 3-2a deduces a = 2 {an} = 3,4,5
{an}=a+2(a>=1)