Question

Write an equation that can be used to find the difference “d” between the first and last numbers in any row “r”. in the new triangle I made

Answer 1

Answer:

(r-1)d

Explanation:

The nth term of any arithmetic series is obtained using the formula:

$T_n=a+(n-1)d$

For any row, r (where r is the number of rows)

The difference between the first and last numbers in any row will be:

$(r-1)d$

Where:

• d=common difference

• r=number of rows.

For an illustration, the difference between the first and last term in the fourth row:

Number of rows = 4

Common difference = 5

$\begin{gathered} (4-1)(5) \\ =3(5) \\ =15 \end{gathered}$

Check: 46-31 = 15