Question

Which of the following equations could be used to solve for the tenth term of the following sequence? 15, 13, 11, 9, ...

Answer 1

Answer:

Equations that could be used to solve for the tenth term of the sequence:

15, 13, 11, 9, ...    is  

b) A(10) = 15 + 9(-2)

Step-by-step explanation:

We are given a sequence:

 15,13,11,9,...

The above sequence is an arithmetic progression with

first term=A(1)=15 and common difference=d=-2

Now, the nth term of an arithmetic progression is determined by the formula

A(n)= A(1)+(n-1)d

⇒  A(10)=  15+9(-2)

Hence, the correct option is:

  b) A(10) = 15 + 9(-2)

Answer 2

Answer

b) A(10) = 15 + 9(-2)

Explanation

15, 13, 11, 9, ...  This is an arithmetic sequence.

The common difference = 13 - 15 = -2

                                     or = 9 - 11 = -2

The first term of the sequence = 15.

The nth term of an arithmetic sequence is given by:

Tn = a + (n - 1)d

∴ T₁₀ = 15 + (10 - 1)(-2)

        = 15 + (9 × -2)  ⇒ This is the expression you need.

        = 15 + -18

       = -3