2 câu trả lời
Đáp án:
`(-11)/20+9/12`
`=(-11)/20+3/4`
`= (-11)/20 + 15/20`
`= [(-11) + 15]/20`
`= 4/20`
`= 1/5`
`#dariana`
`( -11 )/20 + 9/12`
`= ( -11 )/20 + 3/4`
`= ( -11 )/20 + ( 3 xx 5 )/( 4 xx 5 )`
`= ( -11 )/20 + 15/20`
`= [ ( -11 ) + 15 ]/20`
`= 4/20`
`= 1/5`
$\text{#lknhatminh0322}$