-[-30]-[-x]=-13
[-34]-x=-[-45]
-[-x]+[-15]=[-12]
-15-x=-[-7]
tìm x biết:
a) - (-30) - (-x) = - (+13)
b) - (+12) - (+x) = 20
c) (-34) -x= - (-45)
d) - (-x) + (-15) = (-12)
e) (-15) -x = - (-7)
bn đang từng câu 1 thôi lm thế này chắc chết mất
a) - (30) - (-x) =-|-13|
b) -12 - 4x =20
c) -34 - x =-(-45)
d) -(- x) - 15 = -12
e) -15 - x + 3x = -(-1)
a) (-30) - (x) = \(-|-13|\)
(-30)-(x)=-13
x=(-30)-(-13)
x=-17
b
b) -12-4x=20
4x=(-12)-20
4x=32
x=32:4
x=8
vậy x=8
c)-34-x=-(-45)
-34-x=45
x=-34-45
x=79
vậy x=79
d)-(-x)-15=-12
x-15=-12
x =-12+15
x =3
vậy x=3
e)-15-x+3x=(-1)
-15-3x=(-1)
-18x=(-1)
đến đây bn làm nốt nhé
e) -15 -x + 3x= -(-1)
-15 -x + 3x= 1
-15 + 2x =1
2x =1+ 15
2x =16
x=16: 2
x=8
Vậy x= 8
Bài 1 : Tìm x
1/-(-30)-(-x)=-(+13)
2/ -(+12)-(+x)=-(+13)
3/ (-34)-x=-(-45)
4/-(-x)+(-15)=(-12)
5/-15-x=-(-7)
Bài 2 : Tính
1/ (-15)-/-10/+/-9/-/-5/
2/14-(-13)-(-21)+(-32)
3/(-12)-(-17)-(-21)+(-32)
4/-/-14/ + /-10/-(-12)+(-8)
5/-(-11)+(-15)+(+13)-21
giúp mình với mình đang cần gấp !!!!!
Bài 1 : Tìm x
1/-(-30)-(-x)=-(+13)
⇒30+x=-13
⇒x=-13-30
⇒x=-43
2/ -(+12)-(+x)=-(+13)
⇒-12-x=-13
⇒x=-12+13
⇒x=1
3/ (-34)-x=-(-45)
⇒x=-34-45
⇒x=-79
4/-(-x)+(-15)=(-12)
⇒x-15=-12
⇒x=-12+15
⇒x=3
5/-15-x=-(-7)
⇒x=-15-7
⇒x=-22
Bài 2 : Tính
1/ (-15)-/-10/+/-9/-/-5/
=-15-10+9-5
=-21
2/14-(-13)-(-21)+(-32)
=14+13+21-32
=16
3/(-12)-(-17)-(-21)+(-32)
= -12+17+21-32
=-6
4/-/-14/ + /-10/-(-12)+(-8)
=-14+10+12-8
=0
5/-(-11)+(-15)+(+13)-21
=11-15+13-21
=-12
49 (6x-12 ) = 0
17 (15x- 45) = 0
105 (17x-34 ) =0
57 (9x-27) = 0
25+(15 - x) = 30
3 (x+7)- 15 =27
49 (6x-12 ) = 0 17 (15x-45) =0 105 ( 17x-34 ) = 0 57 ( 9x -27 ) = 0
6x -12 = 0 15x -45 = 0 17x - 34 = 0 9x - 27 = 0
6x = 12 15x = 45 17x = 34 9x = 27
x = 2 x =3 x = 2 x = 3
25 + ( 15 - x ) =30 3 ( x + 7 ) -15 =27
15 - x = 25 3 ( x + 7 ) = 42 ( k cho mình nhé )
x = -10 x + 7 = 14
x = 7
(x-15)-(x-3)=-(x+17)-1
-(x-12)-(x-5)=-(4-x)+13
34-(x-7)=x+15-(x+23)
(x-15) - (x-3) = -(x+17) - 1 <=> x-15-x+3 = -x-17-1 <=> x = -6
-(x-12) - (x-5) = -(4-x) + 13 <=> -x+12-x+5 = -4+x+13 <=> -3x = -8 => x = 8/3
34 - (x-7) = x+15 - (x+23) <=> 34-x+7 = x+15-x-23 <=> -x = -49 <=> x = 49
Tính nhẩm
46 x 99 34 x 11 25 x 12 15 x 4 45 x 6 13 x 99 16 x 19 35 x 98
125 x 16 47 x 101
\(46\cdot99\)
\(=46\cdot\left(100-1\right)\)
\(=46\cdot100-46\)
\(=4600-46\)
\(=4554\)
___________
\(34\cdot11\)
\(=34\cdot\left(10+1\right)\)
\(=34\cdot10+34\)
\(=340+34\)
\(=374\)
___________
\(25\cdot12\)
\(=5\cdot5\cdot12\)
\(=5\cdot60\)
\(=300\)
__________
\(15\cdot4\)
\(=15\cdot2\cdot2\)
\(=30\cdot2\)
\(=60\)
____________
\(45\cdot6\)
\(=45\cdot2\cdot3\)
\(=90\cdot3\)
\(=2700\)
________
\(13\cdot99\)
\(=13\cdot\left(100-1\right)\)
\(=13\cdot100-13\)
\(=1300-13\)
\(=1287\)
______________
\(16\cdot19\)
\(=16\cdot\left(20-1\right)\)
\(=16\cdot20-16\)
\(=320-16\)
\(=304\)
_____________
\(35\cdot98\)
\(=35\cdot\left(100-2\right)\)
\(=35\cdot100-35\cdot2\)
\(=3500-70\)
\(=3430\)
____________
\(125\cdot16\)
\(=125\cdot8\cdot2\)
\(=1000\cdot2\)
\(=2000\)
___________
\(47\cdot101\)
\(=47\cdot\left(100+1\right)\)
\(=47\cdot100+47\)
\(=4700+47\)
\(=4747\)
46 x 99 =4554 , 34 x 11 = 374 , 25 x 12 =- 300 , 15 x 4 = 60 , 45 x 6 = 270 , 13 x 99 = 1287 , 16 x 19 = 304
35 x 98 = 3430 , 125 x 16 = 2000 , 47 x 101 = 4747
Tim x
A)x+12/15=7/5
B)x-6/8=3/15
C)x:17/25=15/34
D)1/5×x=9/45
a )
\(x+\frac{12}{15}=\frac{7}{5}\)
\(\Rightarrow x=\frac{7}{5}-\frac{12}{15}\)
\(\Rightarrow x=\frac{7}{5}-\frac{4}{5}\)
\(\Rightarrow x=\frac{3}{5}\)
Vậy \(x=\frac{3}{5}\)
b )
\(x-\frac{6}{8}=\frac{3}{15}\)
\(\Rightarrow x-\frac{3}{4}=\frac{1}{5}\)
\(\Rightarrow x=\frac{1}{5}+\frac{3}{4}\)
\(\Rightarrow x=\frac{4}{20}+\frac{15}{20}\)
\(\Rightarrow x=\frac{19}{20}\)
Vậy \(x=\frac{19}{20}\)
~ Ủng hộ nhé
\(x+\frac{12}{15}=\frac{7}{5}\)
\(\Rightarrow x=\frac{7}{5}-\frac{12}{15}\)
\(\Rightarrow x=\frac{7}{5}-\frac{4}{5}\)
\(\Rightarrow x=\frac{3}{5}\)
c )
\(x:\frac{17}{25}=\frac{15}{34}\)
\(\Rightarrow x=\frac{15}{34}\times\frac{17}{25}\)
\(\Rightarrow x=\frac{3}{10}\)
Vậy \(x=\frac{3}{10}\)
d )
\(\frac{1}{5}\times x=\frac{9}{45}\)
\(\Rightarrow x=\frac{9}{45}:\frac{1}{5}\)
\(\Rightarrow x=\frac{9}{45}\times5\)
\(\Rightarrow x=\frac{9}{5}\)
Vậy \(x=\frac{9}{5}\)
~ Ủng hộ nhé
Bài 4: Tìm x, biết:
a) 11 + x : 5 = 13 b) 15 + (7 – x) = 19
c) 12 + 3.(x – 5) = 30 d) 17 + (x + 4) : 3 = 21
Bài 5: Tính hợp lí:
a) 120.15 + 12.470 + 12.38.10 b) 13.58.4 + 32.26.2 + 52.10
c) 3,2.990 + 32 d) 45.(13 + 78) + 9.(87 + 22).5
e) (24 + 72 + 36 + 60) : 12
f) (2 + 4 + 6 + … + 100).(36.333 – 108.111)
1.
a.
11 + x : 5 = 13
x : 5 = 13 - 11
x : 5 = 2
x = 2 . 5
x = 10
Bài 4: Tìm x, biết:
a) 11 + x : 5 = 13
x : 5 = 2
x = 10
b) 15 + (7 – x) = 19
7 - x = 4
x = 3
c) 12 + 3.(x – 5) = 30
3 ( x - 5 ) = 18
x - 5 = 6
x = 11
d) 17 + (x + 4) : 3 = 21
( x + 4 ) : 3 = 4
x + 4 = 12
x = 8
X : 7 + 20 = 17 x 49 + 17 x 51 287 - ( X + 34) x 3 - 25 = 142 13 x X + 15 x X + 12 x X = 120
1) x : 7 + 20 = 17 x 49 + 17 x 51
x : 7 +20 = 17 x ( 49+51)
x : 7 +20 =1700
x : 7 = 1700 - 20 =1680
x = 1680 x 7 =11 760
2) 287 - ( x+ 34) x 3 - 25 = 142
287-(x+34)x3 = 142 + 25 =167
( x+34) x 3 = 287 - 167=120
x + 34 = ``120 : 3 =40
x = 40 - 34 = 6
3)13x + 15x + 12x = 120
40x = 120
x = 120 : 40 = 3