\((85\dfrac{7}{30}-83\dfrac{5}{18}):2\dfrac{2}{3}=0,01x:4\)
Tim x
a) (85 và 7/30 - 83 và 5/18) : 2 và 2/3 = 0,01x : 4
b) [(6 và 3/5 - 3 và 3/14) . 2,5)] : (21 - 1,25) = x : 5 và 5/6
b: \(\left[\left(6+\dfrac{3}{5}-3-\dfrac{3}{14}\right)\cdot\dfrac{2}{5}\right]:\left(21-1.25\right)=x:\left(5+\dfrac{5}{6}\right)\)
\(\Leftrightarrow x:\dfrac{35}{6}=\dfrac{237}{175}:\dfrac{79}{4}\)
\(\Leftrightarrow x:\dfrac{35}{6}=\dfrac{12}{175}\)
\(\Leftrightarrow x=\dfrac{2}{5}\)
tìm x,biết
A) 1 1/3 /0,8=2 2/3/(0,1*x)
B) (85 7/30 -83 5/18) /2 2/3= 0,01X/4
Giải các phương trình sau
1)\(\dfrac{x+1}{85}+\dfrac{x+3}{83}=\dfrac{x+5}{81}+\dfrac{x+7}{79}\)
2)\(\dfrac{x-1}{2015}-\dfrac{x+3}{2011}=\dfrac{x+7}{2007}-\dfrac{x+11}{2003}\)
3)\(\dfrac{x+4}{4}-\dfrac{x-3}{6}=\dfrac{x}{3}\)
4)\(x-\dfrac{x+1}{3}=\dfrac{2x+1}{5}\)
5) \(\dfrac{2x-7}{5}+\dfrac{x+11}{2}=-4\)
giúp em vs ạ, em đang cần gấpem c.ơn trước ạ
1: \(\Leftrightarrow\left(\dfrac{x+1}{85}+1\right)+\left(\dfrac{x+3}{83}+1\right)=\left(\dfrac{x+5}{81}+1\right)+\left(\dfrac{x+7}{79}+1\right)\)
=>x+86=0
=>x=-86
2: \(\Leftrightarrow\left(\dfrac{x-1}{2015}+1\right)-\left(\dfrac{x+3}{2011}+1\right)=\left(\dfrac{x+7}{2007}+1\right)-\left(\dfrac{x+11}{2003}+1\right)\)
=>x+2014=0
=>x=-2014
3: \(\Leftrightarrow3\left(x+4\right)-2\left(x-3\right)=4x\)
=>4x=3x+12-2x+6
=>4x=x+18
=>3x=18
=>x=6
4: \(\Leftrightarrow15x-5\left(x+1\right)=3\left(2x+1\right)\)
=>15x-5x-5=6x+3
=>10x-5=6x+3
=>4x=8
=>x=2
5: \(\Leftrightarrow2\left(2x-7\right)+5\left(x+11\right)=-40\)
=>4x-14+5x+55=-40
=>9x+41=-40
=>x=-9
Tìm x :
a . (85 7/30 - 83 5/18 ) : 2 2/3 = 0,01x : 4
b . 36 : 2x = 3 2/3 : 3/5
Các số kiểu như 85 7/30 hay 83 5/18 2 2/3 đều là hỗn số nghen ^_^
3 2/3 cũng z nhé
Đều là hỗn số
1.a)Tính 12,5% của :
\(A=\dfrac{\left(85\dfrac{7}{30}-83\dfrac{5}{18}\right)\div2\dfrac{2}{3}}{0,04}\)
b) Tính 5% của :
\(B=\dfrac{\left(6\dfrac{3}{5}-3\dfrac{3}{14}\right).5\dfrac{5}{6}}{\left(21-1,25\right)\div2,5}\)
2. Tìm 12% của tổng \(\dfrac{3}{4}\)M+\(\dfrac{1}{3}\)N , biết :
\(M=\dfrac{3\div\dfrac{2}{3}-0,09\div\left(0,15\div2\dfrac{1}{2}\right)}{0,32.6+0,03-\left(5,3-3,88\right)+0,67}\)
\(N=\dfrac{\left(2,1-1,965\right)\div\left(1,2.0,045\right)}{0,00325\div0,013}-\dfrac{1\div0,25}{1,6.0,625}\)
Bài 1:
a: \(A=\dfrac{\left(85+\dfrac{7}{30}-83-\dfrac{5}{18}\right):\dfrac{8}{3}}{\dfrac{1}{25}}\)
\(=\left(2+\dfrac{7}{30}-\dfrac{5}{18}\right)\cdot\dfrac{3}{8}\cdot25\)
\(=\dfrac{180+21-25}{90}\cdot\dfrac{75}{8}\)
\(=\dfrac{176}{90}\cdot\dfrac{75}{8}=\dfrac{55}{3}\)
=>12,5% của A là 55/8x1/8=55/64
b: \(B=\dfrac{\left(6+\dfrac{3}{5}-3-\dfrac{3}{14}\right)\cdot\dfrac{36}{5}}{19.75:2.5}\)
\(=\dfrac{\left(3+\dfrac{27}{70}\right)\cdot\dfrac{36}{5}}{\dfrac{79}{10}}\)
\(=\dfrac{\dfrac{210+27}{70}\cdot\dfrac{36}{5}}{\dfrac{79}{10}}\)
\(=\dfrac{4266}{175}\cdot\dfrac{10}{79}=\dfrac{108}{35}\)
=>5% là 108/35x1/20=27/175
Tính
a.\(\dfrac{4}{9}+\dfrac{3}{7}\) \(\dfrac{3}{4}+\dfrac{7}{24}\) \(\dfrac{1}{3}+\dfrac{2}{9}+\dfrac{4}{27}\)
b.\(\dfrac{5}{6}-\dfrac{3}{8}\) \(\dfrac{7}{15}-\dfrac{11}{30}\) \(\dfrac{2}{3}+\dfrac{1}{6}-\dfrac{7}{12}\)
c.\(\dfrac{18}{25}\times\dfrac{15}{6}\) \(\dfrac{30}{49}:\dfrac{6}{7}\) \(\dfrac{1}{2}\times\dfrac{3}{4}:\dfrac{6}{5}\)
d.\(8\times\dfrac{3}{5}:\dfrac{12}{5}\) \(4:\dfrac{9}{5}:\dfrac{10}{3}\)
3 bn đầu tiên xong mik sẽ tick
a: 4/9+3/7=28/63+27/63=55/63
3/4+7/24=18/24+7/24=25/24
1/3+2/9+4/27=9/27+6/27+4/27=19/27
b: 5/6-3/8=20/24-9/24=11/24
7/15-11/30=14/30-11/30=3/30=1/10
2/3+1/6-7/12
=8/12+2/12-7/12
=3/12=1/4
c: 18/25*15/6=15/25*18/6=3*3/5=9/5
30/49:6/7=30/49*7/6=210/294=5/7
1/2*3/4:6/5=3/8*5/6=15/48=5/16
d: 8*3/5:12/5=24/5*5/12=2
4:9/5:10/3=4*5/9*3/10=2/3
Câu 1 :\(\dfrac{-5}{7}.\dfrac{7}{-45}\);\(\dfrac{-3}{10}.\left(-30\right)\);\(-12.\dfrac{-2}{36}\)
Câu 2: \(\dfrac{3}{4}+\dfrac{1}{8}.\dfrac{-16}{5};\dfrac{7}{15}-\dfrac{18}{21}.\dfrac{7}{9}\)
Câu 3: \(\left(\dfrac{-5}{9}+\dfrac{3}{5}\right).\dfrac{3}{10};\left(\dfrac{3}{9}-\dfrac{2}{5}\right).\dfrac{-3}{10}\)
Câu 4: \(\left(\dfrac{3}{7}+\dfrac{1}{3}\right).\left(\dfrac{1}{8}-\dfrac{1}{2}\right);\left(\dfrac{-9}{12}-\dfrac{16}{30}\right).\left(\dfrac{-18}{22}-\dfrac{6}{11}\right)\)
Càn gấp
Câu 1:
\(-\dfrac{5}{7}\cdot\dfrac{7}{-45}=\dfrac{1}{9}\) ; \(-\dfrac{3}{10}\cdot-30=9\) ; \(-12\cdot-\dfrac{2}{36}=\dfrac{2}{3}\)
Caau2;3;4;5,... tự bấm máy tính là ra
\(\dfrac{-2}{45}:\dfrac{8}{3}=0,01x:4\)
\(\dfrac{-2}{45}:\dfrac{8}{3}=0,01x:4\)
\(0,01x:4=\dfrac{-2}{45}\times\dfrac{3}{8}\)
\(0,01x:4=\dfrac{-6}{360}\)
\(0,01x:4=\dfrac{-1}{60}\)
\(0,01x=\dfrac{-1}{60}\times\dfrac{1}{4}\)
\(0,01x=\dfrac{-1}{240}\)
\(x=\dfrac{-1}{240}:0,01\)
\(x=\dfrac{-1}{240}\times100\)
\(x=\dfrac{-100}{240}=-2,4\)
\(\dfrac{-2}{45}:\dfrac{8}{3}=0,01x:4\)
\(\dfrac{-2}{45}\times\dfrac{3}{8}=0,01x:4\)
\(\dfrac{-6}{360}=0,01x:4\)
\(\dfrac{-1}{60}=0,01x:4\)
\(0,01x=\dfrac{-1}{60}\times\dfrac{4}{1}\)
\(0,01x=\dfrac{-4}{60}\)
\(0,01x=\dfrac{-1}{15}\)
\(x=\dfrac{-1}{15}:0,01\)
\(x=\dfrac{-1}{15}\times100\)
\(x=\dfrac{-100}{15}=\dfrac{-20}{3}\)
Vậy \(x=\dfrac{-20}{3}\).
Giải Phương trình
1)\(\dfrac{99-x}{101}+\dfrac{97-x}{103}+\dfrac{95-x}{105}+\dfrac{93-x}{107}=4\)
2)\(\dfrac{x+14}{86}+\dfrac{x+15}{85}+\dfrac{x+16}{84}+\dfrac{x+17}{83}+\dfrac{x+116}{4}=0\)
3)\(x+\dfrac{2x+\dfrac{x-1}{5}}{3}=1-\dfrac{3x-\dfrac{1-2x}{3}}{5}\)
Bài 1:
\(\frac{99-x}{101}+\frac{97-x}{103}+\frac{95-x}{105}+\frac{93-x}{107}=-4\)
\(\Leftrightarrow \frac{99-x}{101}+1+\frac{97-x}{103}+1+\frac{95-x}{105}+1+\frac{93-x}{107}+1=0\)
\(\Leftrightarrow \frac{99-x+101}{101}+\frac{97-x+103}{103}+\frac{95-x+105}{105}+\frac{93-x+107}{107}=0\)
\(\Leftrightarrow \frac{200-x}{101}+\frac{200-x}{103}+\frac{200-x}{105}+\frac{200-x}{107}=0\)
\(\Leftrightarrow (200-x)\left(\frac{1}{101}+\frac{1}{103}+\frac{1}{105}+\frac{1}{107}\right)=0\)
Vì \(\frac{1}{101}+\frac{1}{103}+\frac{1}{105}+\frac{1}{107}\neq 0\) nên suy ra \(200-x=0\Rightarrow x=200\)
Bài 2:
\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+116}{4}=0\)
\(\Leftrightarrow \frac{x+14}{86}+1+\frac{x+15}{85}+1+\frac{x+16}{84}+1+\frac{x+17}{83}+1+\frac{x+116}{4}-4=0\)
\(\Leftrightarrow \frac{x+100}{86}+\frac{x+100}{85}+\frac{x+100}{84}+\frac{x+100}{83}+\frac{x+100}{4}=0\)
\(\Leftrightarrow (x+100)\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)=0\)
Vì \(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\neq 0\). Do đó \(x+100=0\Rightarrow x=-100\)
1/
99-x/101+97-x/103+95-x/105+93-x/107
\(\Leftrightarrow\)(99-x/101+1)+(97-x/103+1)+(95-x/105+1)+(93-x/107+1)=0
\(\Leftrightarrow\)100-x/101+100-x/103+100-x/105+100-x/107=0
\(\Leftrightarrow\)(100-x)(1/101+1/103+1/105+1/107)=0
\(\Leftrightarrow\)100-x=0\(\Leftrightarrow\)
x=-100