Question

Answer 1

Câu 33

\(\dfrac{2\times76}{10\times19\times23\times4}=\dfrac{2}{10}\times\dfrac{76}{19\times4}\times\dfrac{1}{23}=\dfrac{1}{5\times23}=\dfrac{1}{115}\)

\(\dfrac{3\times64}{15\times16\times7\times4}=\dfrac{3}{15}\times\dfrac{1}{7}\times\dfrac{64}{16\times4}=\dfrac{1}{5}\times\dfrac{1}{7}=\dfrac{1}{35}\)

=>MSCNN là 805

=>Tổng các chữ số là 8+0+5=13

 

Câu 34:

\(\dfrac{45}{60}=\dfrac{45:15}{60:15}=\dfrac{3}{4}=\dfrac{3\times3}{4\times3}=\dfrac{9}{12}\)

\(\dfrac{50}{60}=\dfrac{50:10}{60:10}=\dfrac{5}{6}=\dfrac{5\times2}{6\times2}=\dfrac{10}{12}\)

=>Chọn B

Câu 35: 

Câu 36: \(\dfrac{13}{15}=\dfrac{13\times7}{15\times7}=\dfrac{91}{105}\)

\(\dfrac{11}{7}=\dfrac{11\times15}{7\times15}=\dfrac{165}{105}\)

=>Chọn C