Question

Tinh bang cach thuan tien:

1313     165165      424242

------- x ------------- x ------------

2121     143143      151515

 

Answer 1

\(\frac{1313}{2121}\)x\(\frac{165165}{143143}\)x\(\frac{424242}{151515}\)

=\(\frac{13x101}{21x101}\)X\(\frac{165x1001}{143x1001}\)X\(\frac{42x10101}{15x10101}\)

=\(\frac{13}{21}\)x\(\frac{165}{143}\)x\(\frac{42}{15}\)

=\(\frac{13}{21}\)x\(\frac{15}{13}\)x\(\frac{14}{5}\)

=\(\frac{13x15x14}{21x13x5}\)

=2