Find the sum of arithmetic sequences 4+8+12+16+...+400

Step-by-step explanation:

First term = a =4

Common difference = d = 2nd term - first term

d = 8 - 4 = 4

Last term = l = 400

First we have to fin the number of terms 'n'

l = a + (n-1)d

4 + (n-1)*4 = 400

4 + 4n- 4 = 400

      4n = 400     {Divide both sides by 4}

         n = 400/4

n = 100

0.35

Step-by-step explanation:

in order to do this, you would multiply 720 by 100% .

Multiplying 720 by 100% allows you to be able to use long division → you only multiply 100 by the numerator (the top number of the fraction).

convert 720 to a decimal, simply divide 7 by 20 .