Bài `1`
`a,x/15+7/20=73/60`
`=> x/15= 73/60 - 7/20`
`=> x/15=13/15`
`=> x=13`
`b,9/x + (-6)/35 =33/70`
`=> 9/x = 33/70 - (-6)/35`
`=>9/x = 33/70 + 6/35`
`=> 9/x=9/14`
`=>x=14`
Bài `2`
`a,` \(\dfrac{12}{13}=\dfrac{12\cdot101}{13\cdot101}=\dfrac{1212}{1313}=\dfrac{12\cdot\left(-10101\right)}{13\cdot\left(-10101\right)}=\dfrac{-121212}{-131313}=\dfrac{121213:10101}{131313:10101}=\dfrac{12}{13}\)
`b,`
\(-\dfrac{22}{121}=\dfrac{-2\cdot2}{11\cdot2}=-\dfrac{4}{-22}\\ -\dfrac{10}{55}=\dfrac{-10:5}{55:5}=-\dfrac{2}{11}=-\dfrac{22}{121}\)
Đúng 3
Bình luận (0)
