Question

3/1*4+3/4*7+3/7*10+..+3/40*4+3/43*46

Giúp mình với

cảm ơn các bạn!!!!

Answer 1

= 1 -1/4 +1/4 -1/7 +1/7 -1/10+...+1/40 -1/43 +1/43 -1/46

= 1 -1/46

= 45/46

Answer 2

\(\frac{3}{1.4}+\frac{3}{4.7}+\frac{3}{7.10}+...+\frac{3}{40.43}+\frac{3}{43.46}\)

\(=1-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+...+\frac{1}{40}-\frac{1}{43}+\frac{1}{43}-\frac{1}{46}\)

\(=1-\frac{1}{46}\)

\(=\frac{45}{46}\)

_Chúc bạn học tốt_

Answer 3

3/1×4 + 3/4×7 + 3/7×10 +...+ 3/40×43 + 3/43*46

=1-1/4+1/4-1/7+1/7-1/10+...+1/40-1/43+1/43-1/46

=1-1/46

=46/46-1/46

=45/46