Question

Giải ra cho mình nha, mình đang cần rất gấp.

Answer 1

=1+\(\dfrac{1}{2}\).3+\(\dfrac{1}{3}\).6+\(\dfrac{1}{4}\).10+....+\(\dfrac{1}{16}\).136

= 1+\(\dfrac{3}{2}\)+2+\(\dfrac{5}{2}\)+..+\(\dfrac{17}{2}\)

=(1+2+...+8)+(\(\dfrac{3}{2}\)+\(\dfrac{5}{2}\)+..+\(\dfrac{17}{2}\))

= 36+40=76