5+10+.......+5n=5/2n(n+1) solve?

To solve this equation, we can use the formula for the sum of an arithmetic series:

Sn = n/2 * (a1 + an)

In this case, a1 = 5 and an = 5n. Plugging these values into the formula, we get:

5 + 10 + ... + 5n = n/2 * (5 + 5n)

Expanding the right side of the equation, we get:

n/2 * (5 + 5n) = 5/2n(n+1)

Therefore, the solution to the equation is:

5 + 10 + ... + 5n = 5/2n(n+1)

The given expression is not an equation, so it cannot be solved for a specific value. However, we can simplify the expression as follows:

5 + 10 + ... + 5n = 5/2n(n + 1)

The left-hand side of the expression is an arithmetic series with n terms, where the first term is 5, the common difference is 5, and the last term is 5n. The sum of an arithmetic series can be calculated as follows:

Sum = n/2(first term + last term)

Substituting the given values into the formula, we get:

Sum = n/2(5 + 5n)
Sum = 5n/2(1 + n)
Sum = 5/2n(n + 1)

Therefore, the simplified expression is:

5 + 10 + ... + 5n = 5/2n(n + 1)