\(\frac{254\cdot399-145}{254+399\cdot253}=\frac{\left(253+1\right)\cdot399-145}{254+399\cdot253}\)

\(=\frac{253\cdot399+399-145}{254+399\cdot253}\)

\(=\frac{253\cdot399+254}{254+399\cdot253}\)

\(=1\)

A = \(\dfrac{254\times399-145}{254+399\times253}\)

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

A = \(\dfrac{253\times399+399-145}{254+399\times253}\)

A = \(\dfrac{253\times399+254}{254+399\times253}\)

A = 1 

a) \(254x399-145=\left(250+4\right)\left(400-1\right)-145\)

\(=100000+1600-250-145-4=101600-\left(250+145+4\right)\)

\(=101600-399=101201\)

b) \(254+399x253=254+\left(400-1\right)x\left(250+3\right)\)

\(=254+100000+1200-250-3\)

\(=101454-250-3=101201\)

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

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

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

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

\(\frac{254.399-145}{254+399.253}\)

\(=\frac{253.399+399-145}{254+399.253}\)

\(=\frac{253.399+254}{254+399.253}=1\)

Trả lời

254.399-145/254+399.253

=253.399+399-145/254+399.253

=253.399+254/254+399.253

=1.

a) \(\frac{254.399-145}{254+399.253}\)

\(=\frac{253.399+399-145}{254+399.253}\)

\(=\frac{253.399+254}{254+399.253}\)

\(=1\)

b) tự làm

đáp án lần lượt là

2772

4154

1

1

nha

58 x 42 + 32 x 8 + 5 x 16

= 2436 + 256 + 80

= 2692 + 80

= 2772

456 : 2 x 18 + 456 : 3 - 102 

= 228 x 18 + 152 - 102

= 4104 + 152 - 102 

= 4256 - 102 

= 4154

( 254 x 399 - 145 ) : ( 254 + 399 x 253 )

= ( 101346 - 145 ) : ( 254 + 100947 )

= 101201 : 101201

= 1

( 5932 + 6001 x 5931 ) : ( 5932 x 6001 - 99 )

= ( 5932 + 35591931 ) : ( 35597932 - 99 )

= 35597863 : 35597833

= \(\frac{35597863}{35597833}=1,000000843\)

uh là nhân

a) \(=\dfrac{254x\left(400-1\right)-145}{254+\left(400-1\right)x253}=\dfrac{254x400-254-145}{254+253x400-253}\)

\(=\dfrac{101600-399}{101200+1}=\dfrac{101211}{101201}=\dfrac{101201+10}{101201}=1+\dfrac{10}{101201}\)

b) \(=\dfrac{5392+\left(600+1\right)x5391}{5392x\left(600+1\right)-69}=\dfrac{5392+600x5391+5391}{5392x600+5392-69}\)

\(=\dfrac{10783+3234600}{3235200+5323}=\dfrac{\text{3245383}}{\text{3240523}}=\dfrac{3240523+60}{3240523}=1+\dfrac{60}{3240523}\)

c) \(=\dfrac{1}{2}x\left(\dfrac{1}{2}-\dfrac{1}{4}\right)+\dfrac{1}{2}x\left(\dfrac{1}{4}-\dfrac{1}{8}\right)+\dfrac{1}{32}\)

\(=\dfrac{1}{2}x\left(\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{8}\right)+\dfrac{1}{32}\)

\(=\dfrac{1}{2}x\left(\dfrac{1}{2}-\dfrac{1}{8}\right)+\dfrac{1}{32}=\dfrac{3}{16}+\dfrac{1}{32}=\dfrac{7}{32}\)

      \(\frac{254.399-145}{254+399.253}=\frac{\left(253+1\right).399-145}{254+399.253}\)

                                    \(=\frac{253.399+1.399-145}{254+399.253}\)

                                    \(=\frac{253.399+254}{254+399.253}\)

                                    \(=1.\)

\(\frac{5932+6001.5931}{5932.6001-69}=\frac{5932+6001.5931}{\left(5931+1\right).6001-69}\)

                                    \(=\frac{5932+6001.5931}{5931.6001+1.6001-69}\)

                                    \(=\frac{5932+6001.5931}{5931.6001+5932}\)

                                    \(=1.\)

Câu thứ nhất là: 202292,4291.       ;       Câu thứ hai là: 36011793,2.