Question

Câu 4 : Thực hiện phép tính

a, (2/5-3/4)-2/5

b,-10/11.4/7+-10/11.3/7+1 10/11

 

 

 

Answer 1

(2/5-3/4)-2/5

-7/20-2/5

-3/4

-10/11.4/7+-10/7.3/7+21/11

-10/11.(4/7+3/7)+21/11

-10/11.1+21/11

-10/11+21/11

1

Answer 2

\(a,\left(\frac{2}{5}-\frac{3}{4}\right)-\frac{2}{5}\)

\(=\frac{2}{5}-\frac{3}{4}-\frac{2}{5}\)

\(=\frac{2}{5}-\frac{2}{5}-\frac{3}{4}\)

\(=0-\frac{3}{4}\)

\(=-\frac{3}{4}\)

\(b,\frac{-10}{11}.\frac{4}{7}+\frac{-10}{11}.\frac{3}{7}+1\frac{10}{11}\)

\(=\frac{-10}{11}.\left(\frac{4}{7}+\frac{3}{7}\right)+1\frac{10}{11}\)

\(=\frac{-10}{11}+1+\frac{10}{11}\)

\(=\left(\frac{-10}{11}+\frac{10}{11}\right)+1\)

\(=1\)

Học tốt

Answer 3

Trả lời :

 \(a,\left(\frac{2}{5}-\frac{3}{4}\right)-\frac{2}{5}\)

\(=\frac{2}{5}-\frac{3}{4}-\frac{2}{5}\)

\(=-\frac{3}{4}\)

\(b,-\frac{10}{11}\times\frac{4}{7}+\left(-\frac{10}{11}\right)\times\frac{3}{7}+1\times\left(-\frac{10}{11}\right)\)

\(=\left(-\frac{10}{11}\right)\times\left(\frac{4}{7}+\frac{3}{7}+1\right)\)

\(=\left(-\frac{10}{11}\right)\times2\)

\(=-\frac{20}{11}\)