Question

Fifth term of an arithmetic sequence is 24 and its common difference is 3.what is its first term?

Answer 1

Answer:

a1=12

Step-by-step explanation:

a1=a=?  a{n}=24    n=5     d=3

a{n}=a+ (n-1)d

24=a+(5-1)3

24=a + 4*3

24=a + 12

a=12

a1=12

Answer 2

Answer:

12

Step-by-step explanation:

Fifth term of AP = first term+4×common difference

or 24 = first term+4×3

or first term = 24-12

i.e. first term = 12