Calculate the sum of the first n terms of the arithmetic progression (an) a) a, = -4; d = 2; n = 16
please help me

n²-5n

Step-by-step explanation:

The sum of the nth term is expressed as;

Sn =n/2[2a+(n-1)d]

Given

a, = -4; d = 2; n = 16

Sn = n/2[2(-4)+(n-1)2]

Sn =n/2[-8+2n-2]

Sn = n/2[2n-10]

Hence the sum of the nth term is 2n²-10n/2

2n(n-5)/2

= n(n-5)

= n²-5n

The sum of the nth term is n²-5n

it could be 1,3 and more others to create a cylinder.

step-by-step explanation:

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles