Question

Tính nhanh:

\(\frac{-5}{9.13}-\frac{7}{9.25}-\frac{-13}{19.25}-\frac{31}{19.69}\)

Answer 1

\(ĐặtA=\frac{-5}{9.13}-\frac{7}{9.25}-\frac{13}{19.25}-\frac{31}{19.69}\)

\(\frac{-1}{2}.A=\frac{5}{13.18}+\frac{7}{18.25}+\frac{13}{25.38}+\frac{31}{38.69}\)

\(\frac{-1}{2}.A=\frac{1}{13}-\frac{1}{18}+\frac{1}{18}-\frac{1}{25}+\frac{1}{25}-\frac{1}{38}+\frac{1}{38}-\frac{1}{69}\)

\(\frac{-1}{2}.A=\frac{1}{13}-\frac{1}{69}\)

\(\frac{-1}{2}.A=\frac{56}{897}\)

\(A=\frac{56}{897}:\left(-\frac{1}{2}\right)\)

\(A=\frac{56}{897}.\left(-2\right)\)

\(A=\frac{-112}{897}\)

Đề của bn sai nên mk sửa lại

Ủng hộ mk nha ^_^

 

Answer 2

Đặt \(A=\frac{-5}{9.13}-\frac{7}{9.25}-\frac{-13}{19.25}-\frac{31}{19.69}\)

\(\frac{A}{2}=\frac{-5}{18.13}-\frac{7}{18.25}-\frac{-13}{38.25}-\frac{31}{38.69}\)

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