Question

Tính  nhanh:

\(\frac{254x399-145}{254+399x253}\)

 

Answer 1

254 × 399 - 145 / 254 + 399 × 253

= (253 + 1) × 399 - 145 / 254 + 399 × 253

= 253 × 399 + (399 - 145) / 254 + 399 × 253

= 253 × 399 + 254 / 254 + 399 × 253

= 1

Answer 2

\(\frac{254x399-145}{254+399x253}\)

\(=\frac{253x399+399-145}{254+399x253}\)

\(=\frac{253x399+254}{254+399x253}=1\)

Answer 3

\(\frac{254.399-145}{254+399.253}=\frac{254.399-145}{\left(254-1\right).399+254}\)\(=\frac{254.399-145}{254.399-399+254}=\frac{254.399-145}{254.399-145}=1\)

DẤU . LÀ DẤU NHÂN NHA

Answer 4

\(\frac{254\times399-145}{254+399\times253}=\frac{\left(253+1\right)\times399-145}{253\times399+254}\)\(=\frac{253\times399+1\times399-145}{253\times399+254}\)\(=\frac{1\times399-145}{254}=\frac{399-145}{254}=\frac{254}{254}=1\)

Answer 5

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