A finite arithmetic sequence has 12 terms. The last term Is 100 and the common difference is 3. What is the first term

Respuesta :

Answer:

the first term is 67

Step-by-step explanation:

A finite arithmetic sequence has 12 terms. The last term Is 100 and the common difference is 3.

the formula for nth term is

[tex]a_n = a_1 +(n-1)d[/tex]

Equation for 12th term is

[tex]a_{12} = a_1 +(12-1)d[/tex]

a_12 is the last term, a1 is the first term and d is the common difference

a12= 100, d= 3

[tex]100 = a_1 +(11)3[/tex]

[tex]100 = a_1 +33[/tex]

Subtract 33 from both sides

a_1= 67

So the first term is 67