Can you solve this problem, and is there an easier way to write the equation?

There is an easier way to do this.

Factor 5 out of each term of your

expression to get

5[1+2 + 3 + ... + 15]

and

1 + 2 + ... + 15 = 15*16/2 = 120.

So the answer to your problem is 5*120 = 600.

There is a general equation to solve this problem for as many terms as you want (not just 15):

 The summation or ∑ is:

   ∑ 5•1 + 5•2 + 5•3 + 5•4 + ∙ ∙ ∙ = 5 • ∑ 1 + 2 + 3 + 4 + ∙ ∙ ∙

  = 5 • [n•(n + 1) ⁄ 2] where "n" is nth term to be added. In your case n = 15 so then:

            ∑ = 5 • [15 • (15 + 1) ⁄ 2] = 600

this is the same as taking 5x(1+2+3+4...+15)

so add the numbers 1 through 15 and multiply by 5

the answer comes out to 120*5 or 600

And the answer is yes there is an easier way to write the question. It's called sigma notation

What you do is write the capital Greek letter sigma. Under it you write x=1, above it you write 15, and to the right of it you write 5x.

What this means is that your starting value for x is 1, your ending value is 15. For each integral value of x (integers) you multiply it by 5 and add all the values up. Once again this is known as sigma notation.

By the distributive property, that's the same as (1 + 2 + 3 + ... + 15) * 5

That should help things a lot