2 câu trả lời
`(12 xx 15 xx 17)/( 6 xx 34 xx 45)`
`= ( 2 xx 6 xx 15 xx 17)/( 6 xx 2 xx 17 xx 15 xx 3 )`
`= 1/3`
`(12 × 15 × 17)/( 6 × 34 × 45)`
`= ( 2 × 6 × 15 × 17 )/( 6 × 2 × 17 × 15 × 3 )`
`= ( cancel{2} × cancel{6} × cancel{15} × cancel{17} )/( cancel{6} × cancel{2} × cancel{17} × cancel{15} × 3)`
`= 1/3`