`a) ( 15 xx 14 - 1 )/( 13 xx 15 + 14 )`

`= ( 15 xx ( 13 + 1 ) - 1 )/( 13 xx 15 + 14 )`

`= ( 15 xx 13 + 15 - 1 )/( 13 xx 15 + 14 )`

`= ( 15 xx 13 + 14 )/( 13 xx 15 + 14 )`

`= 1`

`b) ( 64 xx 50 + 44 xx 100 )/( 27 xx 38 + 146 xx 19 )`

`= ( 32 xx 2 xx 50 + 44 xx 100 )/( 27 xx 38 + 73 xx 2 xx 19 )`

`= ( 32 xx 100 + 44 xx 100 )/( 27 xx 38 + 73 xx 38 )`

`= ( 100 xx ( 32 + 44 ) )/( 38 xx ( 27 + 73 ) )`

`= ( 100 xx 76 )/( 38 xx 100 )`

`= 76/38 = 2`

Đáp án:

Giải thích các bước giải:

 a)$\frac{15.14-1}{13.15+14}$ 

$\frac{15.(13+1)-1}{13.15+14}$ 

=$\frac{15.13+15-1}{13.15+14}$ 

=$\frac{15.13+14}{13.15+14}$ 

=1

b)$\frac{64.50+44.100}{27.38+146.19}$ 

=$\frac{32.2.50+44.100}{27.38.73.2.19}$ 

=$\frac{32.100+44.100}{27.38+73.38}$ 

=$\frac{100.(32+44)}{38.(27+73)}$ 

=$\frac{100.76}{38.100}$ 

=2

Xin hay nhất~~