Question

ai có thể giúp mình giải bài này với :

3/1.4 + 3/4.7 + 3/7.10 +...+ 3/40.43

Answer 1

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

=1/1-1/43

=42/43

(^_^)

Answer 2

\(\frac{3}{1.4}+\frac{3}{4.7}+\frac{3}{7.10}+...+\frac{3}{40.43}=\frac{1}{1}-\frac{1}{4}+\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+...+\frac{1}{40}-\frac{1}{43}\)

\(=1-\frac{1}{43}=\frac{42}{43}\)

Answer 3

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

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

=   \(1-\frac{1}{43}\)

=   \(\frac{42}{43}\)