i don't understand :(

sorry but where is B  :(

3 cats :)

30 percent :)

It is too long so I don't want to write too much

use The nature of multiplication with addition to divide \(\dfrac{1}{277}\)

The answer is \(\dfrac{1}{277x257}\)

A=\(\dfrac{1}{1x2}+\dfrac{1}{2x3}+...+\dfrac{1}{999x1000}\)

A=\(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{999}-\dfrac{1}{1000}\)

A=\(1-\dfrac{1}{1000}\)

A=\(\dfrac{999}{1000}\)

A=\(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{1}{16}+\dfrac{1}{32}+\dfrac{1}{64}+\dfrac{1}{128}\)

128A=64+32+16+8+4+2+1

128A=127

A=\(\dfrac{127}{128}\)

A=3+3²+3³+...+3²⁰⁰⁰

3A=3²+3³+3⁴+...+3²⁰⁰¹

2A=3²⁰⁰¹-3

A=\(\dfrac{3^{2001}-3}{2}\)

a) x⁷

b) a⁹

c) (m+n)⁵

d) x³ⁿ⁺⁴

e)27m⁶n⁹