For a positive integer

MATHEMATICS · Single correct · ISC · Mathematics · Algebra · Algebra

Problem

n

, which of the following expressions equals

\displaystyle\sum_{k=1}^{n}(5k-2)

? (a)

\displaystyle\frac{5n(n+1)}{2}

(b)

\displaystyle\frac{5n(n+1)}{2}-2

(c)

\displaystyle\frac{n(5n+1)}{2}

(d)

\displaystyle\frac{n(5n+6)}{2}