Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) \(\frac{12\cdot13}{5\cdot24}=\frac{13}{5\cdot2}=\frac{13}{10}\)
b)\(\frac{25\cdot17+25\cdot12}{29\cdot13+29\cdot14}=\frac{25\cdot\left(17+12\right)}{29\left(13+14\right)}=\frac{25\cdot29}{29\cdot27}=\frac{25}{27}\)
a, \(\frac{12.13}{5.24}=\frac{12.13}{5.2.12}=\frac{13}{10}\)
b, \(\frac{25.17+25.12}{29.13+29.14}=\frac{25.\left(17+12\right)}{29.\left(13+14\right)}=\frac{25.29}{29.27}=\frac{25}{27}\)
\(\dfrac{25.12+25.17}{29.\left(-13\right)+29.\left(-27\right)}=\dfrac{25.\left(12+17\right)}{29.\left[\left(-13\right)+\left(-17\right)\right]}=\dfrac{25.29}{29.\left(-30\right)}=\dfrac{725}{-870}\)
Từ đề bài ta có :
\(\frac{13+n}{29+n}=\frac{5}{9}\)
\(\Rightarrow9\left(13+n\right)=5\left(29+n\right)\)
\(\Rightarrow117+9n=145+5n\)
\(\Rightarrow9n-5n=145-117\)
\(\Rightarrow4n=28\)
\(\Rightarrow n=7\)
Vậy n = 7
Thử lại : \(\frac{13+n}{29+n}=\frac{13+7}{29+7}=\frac{20}{36}=\frac{5}{9}\)(đúng)
Ban nay to viet (dau gach cheo ''/'') nay la phan nhe !
Theo de bai ta co:
29+n/51+n=2/3
=>(29+n).3=(51+n).2
=>29.3+3n=51.2+2n
=>87+3n=102+2n
=>3n-2n=102-87
=>(3-2)n=15
=>1n=15
=>n=15
Vay n = 15
a, 24/-42 = -24/42= -4x6/7x6 =-4/7
b,-24/36 = -2x12/3x12 =-2/3
c,-8/56= -1x8/7x8 =-1/7
d,29/-87= -29/87 =-1x29/3x29 =-1/3
e, -3x35/42x9 =-1x3x5x7/6x7x3x3 =-1x5/3x6 =-5/18
f,-45045 / 6006000=-45x1001 /6000x1001=45/6000=3x15/15x400=3/400
\(a.\frac{-4}{7},b.\frac{-2}{3},c.\frac{-1}{7},d.\frac{-1}{3},e.\frac{-5}{18},f.\frac{-3}{400}\)
7+85/9+29 = 92/38 = 46/19