Tim x:
a, [x+1] + [x+2] + [x+3] + ... + [x+100] bang 206050
b, [1-3/10-x] : [19/20-1-2/5]
c, |2x-2| bang x+18
d, | |11-x| +9| - 7 bang 12
tim x
a. 8x+2x bang 25.2 2
b. 5x+2x bang 6 2- 5 0
c. 5x+x bang 150 chia 2+3
d.6x+x bang 5 11 chia 5 9+3 1
timx
a. 5x+3x bang 3 6 chia 3 3.4+12
b. 4x+2x bang 68-2 19 chia 2 16
c. 5x+x bang 39-3 11 chia 3 9
d. 7x-x bang 5 21 chia 5 19 +3.2 2-7 0
1 tim cac so nguyen x,y biet x/7=6/21 -5/y=20/28 1/2=x/12 x/8=-28/32 3/y=12/24 3/4=15/y 2 viet 3 phan so bang phan so -10/15
x+1+2+3+4+5+6+7+8+9+10+11+...+100=250000
Hoi x bang bao nhieu
x+1+2+3+....+100 = 250000
x + 5050 = 250000
x = 250000 - 5050
x = 2244950
x+1+2+3+....+100 = 250000
x + 5050 = 250000
x = 250000 - 5050
x = 2244950
@@ hacker
x+1+2+3+4+5+6+7+.....+100=250000
suy ra x+(1+100)x100:2=250000
suy ra x+101x50=250000
suy ra x+5050=250000
suy ra x=250000-5050
x=244950
timx
a. 7x-2x bang 6 17 chia 6 15+44 chia 11
b. 3 x bang 9
c. 4 x bang 64
d. 9 x-1 bang 9
e. x 4 bang 16
f. 2 x chia 2 5 bang 1
bai 1 tim x
x-5/6=12/7
x+4/5=8/3
x*3/9=11/7-3/4
5/9:x=1/3+2/5
1 va3/4-x=3/8
15,21-x=5,6+1,2
bai2tinh bang 2 cach
(6,75+3,25)*42
(9,6-4,2)*3,6
x - 5 / 6 = 12 / 7
x = 12 / 7 + 5 / 6
x = 107 / 42
x + 4 / 5 = 8 / 3
x = 8 / 3 - 4 / 5
x = 28 / 15
x * 3 / 9 = 11 / 7 - 3 / 4
x * 3 / 9 = 23 / 28
x = 23 / 28 : 3 / 9
x = 69 / 28
5 / 9 : x = 1 / 3 + 2 / 5
5 / 9 : x = 11 / 15
x = 5 / 9 : 11 / 15
x = 25 / 33
\(1\frac{3}{4}-x=\frac{3}{8}\)
x = 11 / 8
15 , 21 - x = 5 , 6 + 1 , 2
15 , 21 - x = 6 , 8
x = 15 , 21 - 6 , 8
x = 8 , 41
C1 : ( 6 , 75 + 3 , 25 ) * 42
= 10 * 42
= 420
C 2 : ( 6 , 75 + 3 , 25 ) * 42
= 6,75 * 42 + 3,25 * 42
= 283 , 5 + 136 , 5
= 4200
C 1 : ( 9 , 6 - 4 , 2 ) * 3 , 6
= 5 , 4 * 3 , 6
= 19 , 44
C 2 : ( 9 , 6 - 4 , 2 ) * 3 , 6
= 9 , 6 * 3 , 6 - 4 , 2 * 3 , 6
= 34 , 56 - 15 , 12
= 19 , 44
tinh bang cach thuan tien 3/5 x 7/9 + 11/9 x 3/5 - 3/10. B 14/13 : 1/2 + 3/13 x2 -2 x 7/13
a) 3/5x7/9+11/9x3/5
=3/5 x(7/9+11/9)
= 3/5x2
=6/5
b)14/13:1/2+3/13x2-2x7/13
= 14/13 x 2 +3/13 x2 - 2x7/13
=2 x (14/13 +3/13 -7/13)
= 2 x 10/13
= 20/13
a) 3/5 x 7/9 + 11/9 x 3/5 - 3/10
= 3/5 x 7/9 + 11/9 x 3/5 - 3/5 x 2
= 3/5 x ( 7/9 + 11/9 - 2 )
= 3/5 x 0
= 0
b) 14/13 : 1/2 + 3/13 x 2 - 2 x 7/13
= 14/13 x 2/1 + 3/13 x 2 - 2 x 7/13
= ( 14/13 + 3/13 - 7/13 ) x 2
= 10/13 x 2 = 20/13
chẳng hiể gì cả
1. tim cac so nguyen x, y biet
a.\(\dfrac{x}{2}\)bang\(\dfrac{-6}{3}\)
b. \(\dfrac{2}{x}\)bang \(\dfrac{y}{-3}\)
c. \(\dfrac{x}{y}\)bang\(\dfrac{-3}{11}\)
d. \(\dfrac{x}{y-1}\)bang\(\dfrac{5}{-19}\)
a) \(\dfrac{x}{2}=-\dfrac{6}{3}=-2\Rightarrow x=2.\left(-2\right)=-4\)
b) \(\dfrac{2}{x}=\dfrac{y}{-3}\Leftrightarrow y=-\dfrac{6}{x}\) y thuộc Z => x thuộc {+-6;+-3;+-2;+-1}
(x;y) =(-6;1);(-3;2); (-2;3);(-1;6) ; (6;-1);(3-2);(2;-3);(1;-6)
1 tim cac so nguyen x,y biet
x/7=6/21
-5/y=20/28
1/2=x/12
x/8=-28/32
3/y=12/24
3/4=15/y
2 viet 3 phan so bang phan so -10/15