Question

Please help!!!!

Answer 1

Answer:

225

Step-by-step explanation:

Using the basic components of summation ∑

∑n = $\frac{1}{2}$ n(n + 1) and ∑1 = n

Thus

∑ (2n - 1) ← for n = 1 to 15

= ∑2n - ∑1

= 2∑n - ∑1

= 2 ($\frac{1}{2}$ n(n + 1)) - n

= n(n + 1) - n ← Evaluate for n = 15 ( the upper value )

= 15 × 16 - 15

= 240 - 15

= 225