Question

Tính nhanh

Answer 1

a)\(=\dfrac{6\times8\times12\times4\times4}{4\times12\times6\times8}=\dfrac{4}{1}=4\)

b)\(=\dfrac{5\times7\times9\times11}{3\times9\times5\times7\times11}=\dfrac{1}{3}\)

Answer 2

`[ 6 xx 8 xx 12 xx 16 ] / [ 4 xx 12 xx 6 xx 8 ]`

`= [ 6 xx 8 xx 12 xx 4 xx 4 ] / [ 6 xx 8 xx 12 xx 4 ]`

`= 4`

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`[ 5 xx 7 xx 9 xx 11 ] / [ 27 xx 5 xx 7 xx 11 ]`

`= [ 5 xx 7 xx 9 xx 11 ] / [ 5 xx 7 xx 9 xx 11 xx 3 ]`

`= 1 / 3`

Answer 3

\(\dfrac{6x8x12x16}{4x12x6x8}\)=\(\dfrac{16}{4}\)= 4

\(\dfrac{5x7x9x11}{27x5x7x11}\)=\(\dfrac{9}{27}\)=\(\dfrac{1}{3}\)

Cách làm: Nếu ở mẫu số và tử số có 2 số giống nhau thì chúng ta bỏ nó đi

Answer 4

\(\dfrac{6\times8\times12\times16}{4\times12\times6\times8}=\dfrac{6\times8\times12\times4\times4}{4\times12\times6\times8}=4\)

- - - - - - - - - - - - - - - - - - - - - - - 

\(\dfrac{5\times7\times9\times11}{27\times5\times7\times11}=\dfrac{5\times7\times9\times11}{9\times3\times5\times7\times11}=\dfrac{1}{3}\)

Answer 5

=5×7×9×113×9×5×7×11=13

Answer 6