Tính nhanh:

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

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

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

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

\(=\)\(1\)

b) \(\frac{5932+6001.5931}{5932.6001-69}\)

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

\(=\)\(\frac{5932+6001.5931}{5931.6001+6001-69}\)

\(=\)\(\frac{5932+6001.5931}{5932.6001+5932}\)

\(=\)\(1\)

a, 202292,4082

b, 36011793,2

\(\frac{5932+6001.5931}{5932.6001-69}=\frac{6001.5931+5932}{5931.6001+6001-69}=\frac{6001.5931+5932}{6001.5931+5932}=1\)

còn câu a

câu a thế nào vậy

C=\(\frac{1}{2}.\frac{2}{3}.......\frac{2016}{2017}\)

C= CÂU HỎI TƯƠNG TỰ 

=> đcpm 

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

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

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

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

\(A=1\)

\(B=\frac{5932+6001\cdot5931}{5932\cdot6001-69}\)

\(B=\frac{5932+6001\cdot5931}{\left(5931+1\right)\cdot6001-69}\)

\(B=\frac{5932+6001\cdot5931}{5931\cdot6001+\left(6001-69\right)}\)

\(B=\frac{5932+6001\cdot5931}{5931\cdot6001+5932}\)

\(B=1\)

\(C=\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot...\cdot\left(1-\frac{1}{2017}\right)\)

\(C=\frac{1}{2}\cdot\frac{2}{3}\cdot...\cdot\frac{2016}{2017}\)

\(C=\frac{1\cdot2\cdot3\cdot...\cdot2016}{2\cdot3\cdot4\cdot...\cdot2017}\)

\(C=\frac{1}{2017}\)

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

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

a,109/508

b,1

A= 109/508

B=1

A) 0,996

B) 1

Bài của mình làm đúng 100% luôn nha bạn,cứ yên tấm đi không sai đâu

#)Giải :

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

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

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

\(=1\)

B, \(\frac{5932+6001x5931}{5931x6001-69}\)

\(=\frac{5932+6001x5931}{\left(5931+1\right)x6001-69}\)

\(=\frac{5932+6001x5931}{5931x6001+6001-69}\)

\(=\frac{5932+6001x5932}{5932x6001+5932}\)

\(=1\)

         #~Will~be~Pens~#

\(\frac{254x399-145}{254+399x253}=\frac{\left(253+1\right)x399-145}{254+399x253}=\frac{253x399+1x399-145}{254+399x253}=\frac{253x399+254}{254+399x253}\)

\(=1\)

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

=\(\frac{\left(253+1\right)x399-145}{254+399x253}\)

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

=\(\frac{253.399+254}{254+399x253}\)=\(1\)

\(\frac{5932+6001x5931}{5931x6001-69}\)

=\(\frac{5932+6001x5931}{\left(5931+1\right)x6001-69}\)

=\(\frac{5932+6001x5931}{5931x6001+6001-69}\)

=\(\frac{5932+6001x5931}{5931x6001x5932}\)=1

# Hok tốt