Rút gọn các phân số sau:
a) 3 6 ;
b) 30 60 ;
c) − 5 15 .
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) \(\dfrac{11\cdot8-11\cdot3}{17-6}\)
\(=\dfrac{11\cdot\left(8-3\right)}{11}=5\)
b) \(\dfrac{24-12\cdot13}{12+4\cdot9}\)
\(=\dfrac{12\cdot\left(2-13\right)}{12\left(1+3\right)}=\dfrac{-11}{4}\)
a: \(=\dfrac{21\cdot11}{22\cdot9}=\dfrac{1}{2}\cdot\dfrac{7}{3}=\dfrac{7}{6}\)
b: \(=\dfrac{49\cdot8}{10}=49\cdot\dfrac{4}{5}=\dfrac{196}{5}\)
c: \(=\dfrac{12\cdot\left(-4\right)}{32\cdot6}=\dfrac{-48}{192}=-\dfrac{1}{4}\)
a) \(\dfrac{3x^2+6xy}{6x^2}=\dfrac{3x\left(x+2y\right)}{6x^2}=\dfrac{x+2y}{2x}\)
b) \(\dfrac{2x^2-x^3}{x^2-4}=\dfrac{x^2\left(2-x\right)}{\left(x+2\right)\left(x-2\right)}=\dfrac{-x^2}{x+2}\)
c) \(=\dfrac{x+1}{x^3+1}=\dfrac{x+1}{\left(x+1\right)\left(x^2+x+1\right)}=\dfrac{1}{x^2+x+1}\)
`a, (3x^2+6xy)/(6x^2) = (x+2y)/(3x)`
`b, (2x^2-x^3)/(x^2-4) = (x^2(2-x))/((x-2)(x+2))`
`= -x^2/(x+2)`
`c, (x+1)/(x^3+1) = 1/(x^2-x+1)`
a: 12/21=4/7=8/14
4/56=1/14
b: 12/15=4/5=24/30
6/36=1/6=5/30
15/50=3/10=9/30
c: 63/77=9/11=81/99
60/108=5/9=55/99
-18/27=-2/3=-66/99
d: -26/-156=1/6=7/42
49/-14=-7/2=-147/42
32/112=2/7=12/42
a) Cách 1:
\(6(y - x) - 2(x - y)\)
\( = 6y - 6x - 2x + 2y\)
\( = 8y - 8x\)
Cách 2:
\(6(y - x) - 2(x - y)\\= 6(y-x)+2(y-x)\\=(6+2).(y-x)\\=8.(y-x)\\=8y-8x\)
b) \(3{x^2} + x - 4x - 5{x^2}\)
\( = (3{x^2} - 5{x^2}) + (x - 4x)\)
\( = - 2{x^2} - 3x\)
a: \(=\dfrac{12xy^3z^4}{24x^2y^3z^3}=\dfrac{1}{2}\cdot\dfrac{1}{x}\cdot z=\dfrac{z}{2x}\)
b: \(=\dfrac{3\left(x-2\right)}{6x\left(x-2\right)}=\dfrac{1}{2x}\)
\(a,\dfrac{583}{352}=\dfrac{53}{32}\\ b,\dfrac{121212}{313131}=\dfrac{12}{31}\\ c,\dfrac{153.24-153.11}{160-7}=\dfrac{153\left(24-11\right)}{153}=13\)
a ) 3 6 = 3 : 3 6 : 3 = 1 2
b ) 30 60 = 30 : 30 60 : 60 = 1 2
c ) − 5 15 = ( − 5 ) : 5 15 : 5 = − 1 2