Find the sum of the arithmetic sequence.

-1, 2, 5, 8, 11, 14, 17

               S₇  = 16

Step-by-step explanation:

First term = -1

common difference d  = 3 ; n = 7

The sum of first n terms Sₙ = 2 a + (n - 1) d

                     S₇ = 2 × -1 + ( 7 -1 ) 3

                          = - 2 +( 6 × 3)

                          = - 2 + 18

                         = 16

the dimensions are:

step-by-step explanation:

we want to find the dimensions of a rectangular box with volume of

we factor to obtain;

we rewrite the rightmost factor to obtain;

recall that:

we apply difference of two squares formula to obtain;

hence the dimensions are