2/5*x cong x*1/5=2/7.tim x
tim x biet
2/3 chia x/5 cong 5/7 bang 2/7 chia 3/5 cong 9/10
\(\frac{2}{3}:\frac{x}{5}+\frac{5}{7}=\frac{2}{7}:\frac{3}{5}+\frac{9}{10}\)
\(\frac{2}{3}.\frac{5}{x}=\frac{2}{7}.\frac{5}{3}+\frac{9}{10}-\frac{5}{7}\)
\(\frac{10}{3}:x=\frac{10}{21}+\frac{9}{10}-\frac{5}{7}=\frac{100+189-150}{210}=\frac{139}{210}\)
\(x=\frac{700}{139}\)
tim x nha mn
l,[12 nhan 15 - x] nhan 1/4= 120 nhan 1/4
i, [x nhan 0,25 cong 2012 ] nhan 2013 =[50 cong 2012] nhan 2013
k,[ x - 1/2] nhan 5/3 = 7/4 - 1/2
\(\left[12\cdot15-x\right]\cdot\frac{1}{4}=120\cdot\frac{1}{4}\)
\(\Leftrightarrow\left[180-x\right]\cdot\frac{1}{4}=30\)
\(\Leftrightarrow180-x=30:\frac{1}{4}\)
\(\Leftrightarrow180-x=120\)
\(\Leftrightarrow x=60\)
\(\left[x\cdot0,25+2012\right]\cdot2013=\left[50+2012\right]\cdot2013\)
\(\Leftrightarrow x\cdot0,25\cdot2013+2012\cdot2013=2062\cdot2013\)
\(\Leftrightarrow x\cdot\frac{2013}{4}+4050156=4150806\)
\(\Leftrightarrow x\cdot\frac{2013}{4}=100650\)
\(\Leftrightarrow x=100650:\frac{2013}{4}=100650\cdot\frac{4}{2013}=200\)
[X nhan 7 cong 8 ] chia 5 = 10
280 chia [7 cong 3 nhan X] = 4
[ X nhan 5] nhan 19 chia 13= 57
6 nhan [28 - 8] nhan X ] = 72
4 nhan [ 36 - 4 nhan X] = 3,2
[X - 15] nhan 3 chia 12 =6
[ X chia 4 cong 6] nhan 7=70
[ X chia 2 cong 50] chia 5=12
5 nhan [ 7 cong 3 nhan X] = 140
help me ////\\\\\
tim X nha mn jup mk ik mk dg voi lam
a) (x.7 +8):5=10
x.7 +8= 10.5=50
x.7= 50-8=42
x= 42:7=6
b) 280: (7+3.x)=4
7+3.x= 4.280= 1120
3.x= 1120-7 =1113
x= 1113: 3= 371
c) (x.5) .19:13= 57
(x.5). 19= 57.13= 741
x.5= 741: 19= 39
x= 39:5 =7,8
d) 6.(28-8).x = 72
20.x= 72:6= 12
x= 12: 20= 0,6
e) 4. (36-4.x)= 3,2
36-4.x= 32:4= 0,8
-4.x= 0,8- 36= -35,2
x= -35,2 : -4 = 8,8
f) (x-15).3 :12= 6
(x-15).3 = 6. 12= 72
x-15= 72: 3= 24
x= 24+ 15= 39
g) (x:4+ 6) . 7 = 70
x:4+6= 70:7= 10
x:4= 10-6= 4
x= 4.4 = 16
h) (x:2+50) :5= 12
x:2+ 50= 12.5= 60
x:2= 60-50= 10
x= 10.2=20
l) 5.(7+3.x)= 140
7+3.x= 140:5 = 28
3.x= 28-7 =21
x= 21: 3= 7
k cho mình nhe
tim x thuoc n biet ;
g/121 :11-(4 nhan x cong 5) chia 3 =4
h/2x cong 2x+1 = 96
k/34 nhan x +4 =81 x+3
j/(x -5)7=(x-5)9 chu y x nho hon hoac bang 5
l/x2015 =x2016
tim a
a x 5 cong a cong a cong a : 96
a cong a cong a cong a - a x 2 bang 502
7,2 chia 2,4 nhan X= 4,5
X nhan4,8 cong 5,2nhan X= 160
9,15nhan X cong 2,85 nhan X=48
[X nhan 3 cong 4 ] chia 5 =8
[15 nhan 28 - X] chia 2/5= 200 chia 0,4
7 nhan [8 cong 2 nhan X]= 210
X nhan 5,6 cong 4,4 nhan X= 130
[ X - 12] nhan 17 chia 11 = 51
9,15 nhan cong 2,85 nhan X= 48
tim X nha m.n
a ma cai nay mk rat voi nen nhanh jup mk nha
[......] cai nay la dau nghoach nha
1. . 7,2 : 2,4 x X = 4,5
3 x X = 4,5
X = 4,5 : 3
X = 1,5
2. X x 4,8 + 5,2 x X = 160
=> X x ( 5,2 + 4,8 ) = 160
X x 10 = 160
X = 160 : 10
X = 16
3. 9,15 x X + 2,85 x X =48
=> ( 9,15 + 2,85 ) x X = 48
12 x X = 48
X = 48 : 12
X = 4
4. ( X x 3 + 4 ) : 5 = 8
X x 3 + 4 = 8x 5
X x 3 + 4 = 40
X x 3 = 40 - 4
X x 3 = 36
X = 36 : 3
X = 12
5. ( 15 x 28 - x ) : 2/5 = 200 : 0,4
15 x 28 - x = 200 : 0,4 x 2/5
15 x 28 - x = 200
15 x 28 = 200 + x
420 = 200 + x
x = 420 - 200
x = 220
6. 7 x ( 8 + 2 x X ) = 210
8 + 2 x X = 210 : 7
8 + 2x = 30
=> 2x = 30 - 8
2x = 22
x= 22 : 2
x = 11
7. X x 5,6 + 4,4 x X = 130
X x ( 5,6 + 4,4 ) = 130
X x 10 = 130
X = 130 : 10
X = 13
8. ( x - 12 ) x 17 : 11 = 51
x - 12 = 51 x 11 : 17
x - 12 = 33
x = 33 + 12
x = 45
9. 9,15 x X + 2,85 x X = 48
X x ( 9,15 + 2,85 ) = 48
X x 10 = 48
X = 48 : 10
X = 4,8
cau nay ban lam sai
Tim X la so tu nhiên biết : X < 11/3 cong 5/7
tim z,y,z thoa
can x cong can tat ca y tru 1 cong can tat ca z tru 2 bang 1 phan 2 ( x cong y cong z)
tim GTN cua B bang 1 phan x tru can x cong 1
tim x thuoc z de can x cong 1 phan can 3 tru 3 la so nguyen
tinh tong T bang 1 phan can 1 cong can 2 cong 1 phan can 2 cong can 3 cong ... cong den 1 phan can 99 cong can 100
tim x
1/5+x=3/7+1/3
x-1/2=2/3-1/5
3/5 nhân x=2/7+1/4
7/8:x=1/6 nhân 2/3
1 / 5 + x = 3 / 7 + 1 / 3
1 / 5 + x = 16 /21
x = 16 / 21 - 1 / 5
x = 59 / 105
x - 1 / 2 = 2 / 3 - 1 / 5
x - 1 / 2 = 7 / 15
x = 7 / 15 + 1 / 2
x = 29 / 30
3 / 5 * x = 2 / 7+ 1 / 4
3 / 5 * x = 15 / 28
x = 15 / 28 : 3 / 5
x = 25 / 28
7 / 8 : x = 1 / 6 * 2 / 3
7 / 8 : x = 1 / 9
x = 7 / 8 : 1 / 9
x = 63 / 8