Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2. i) 13.x + 15.x + 12.x = 120
=> (13 + 15 + 12).x = 120
=> 40.x = 120
=> x = 120 : 40
=> x = 3
k) 63 + 83 . 9 = (x + 120): x + 209
=> 63 + 747 - 209 = 1 + 120 : x
=> 120 : x + 1 = 601
=> 120 : x = 601 - 1
=> 120 : x = 600
=> x = 120 : 600
=> 1/2
k) 375 - 75.(x - 75) = 300
=> 75.(x - 75) = 375 - 300
=> 75.(x - 75) = 75
=> x - 75 = 1
=> x = 75 + 1
=> x = 76
Bài 2 :
a ) x + 23 = 100 : 2,5
x + 23 = 40
x = 40 - 23
x = 17
Vậy x = 17
b ) 8,4 + 1,6 * x = 7,4 + 2,6
8,4 + 1,6 * x = 10
1,6 * x = 10 - 8,4
1,6 * x = 1,6
x = 1,6 : 1,6
x = 1
Vậy x = 1
c ) ( x - 375 ) : 23 + 35 = 86
( x - 375 ) : 23 = 86 - 35
( x - 375 ) : 23 = 51
x - 375 = 51 * 23
x - 375 = 1173
x = 1173 + 375
x = 1548
Vậy x = 1548
d ) 375 - ( 113 - x ) * 3 = 168
( 113 - x ) * 3 = 375 - 168
( 113 - x ) * 3 = 207
113 - x = 207 : 3
113 - x = 69
x = 113 - 69
x = 44
Vậy x = 44
e ) 2013 - ( x - 1 ) * 13 = 2000
( x - 1 ) * 13 = 2013 - 2000
( x - 1 ) * 13 = 13
x - 1 = 13 : 13
x - 1 = 1
x = 1 + 1
x = 2
Vậy x = 2
g ) x : 7 + 20 = 17 * 49 + 17 * 51
x : 7 + 20 = 17 * ( 49 + 51 )
x : 7 + 20 = 17 * 100
x : 7 + 20 = 1700
x : 7 = 1700 - 20
x : 7 = 1680
x = 1680 * 7
x = 11760
Vậy x = 11760
f ) 987 - ( x + 189 ) : 3 = 537
( x + 189 ) : 3 = 987 - 537
( x + 189 ) : 3 = 450
x + 189 = 450 * 3
x + 189 = 1350
x = 1350 - 189
x = 1161
Vậy x = 1161
Các phần còn lại tương tự
a) 3+2*x=15
2x=15-3
2x=12
x=12:2
x=6
Vậy x=6
b) 24-x=19
x=24-19
x=5
Vậy x=5
c) 29x-13=45
29x=45+13
29x=58
x=58:29
x=2
Vậy x=2
d) 5x-17=38
5x=38+17
5x=55
x=55:5
x=11
Vậy x=11
e) 50-2(x+1)=20
2(x+1)=50-20
2(x+1)=30
x+1+30/2
x+1=15
x=15-1=14
Vậy x=14
f)
1) (x-17)*17=0
x-17=0
x=17
2) 32(x-11)=32
x-11=1
x=12
3) (x-25)-75=0
x-25=75
x=3
4) 575-(6*x+70)=445
6*x+70=130
6*x=60
x=10
5) 315+(125-x)=435
125-x=120
x=5
6) x-105:21=15
x-5=15
x=20
7) (x-105):21=15
x-105=315
x=420
8) (x-38):19=12
x-38=228
x=266
9) (x-15)*(x-19)=0
=>x-15=0 hoặc x-19=0
x=15 hoặc x=19
10) 96-3(x+1)=42
3(x+1)=54
x+1=18
x=17
a) ( x - 17 ) . 17 = 0
=> x - 17 = 0 : 17
=> x - 17 = 0
=> x = 0 + 17
=> x = 17
b) 32 . ( x - 11 ) = 32
=> x - 11 = 32 : 32
=> x - 11 = 1
=> x = 1 + 11
=> x = 12
c) ( x - 25 ) - 75 = 0
=> x - 25 = 0 + 75
=> x - 25 = 75
=> x = 75 + 25
=> x = 100
d) 575 - ( 6 . x + 70 ) = 445
=> 6 . x + 70 = 575 - 445
=> 6 . x + 70 = 130
=> 6 . x = 130 - 70
=> 6 . x = 60
=> x = 60 : 6
=> x = 10
e) 315 + ( 125 - x ) = 435
=> 125 - x = 435 - 315
=> 125 - x = 120
=> x = 125 - 120
=> x = 5
f) x - 105 : 21 = 15
=> x - 5 = 15
=> x = 15 + 5
=> x = 20
g) ( x - 105 ) : 21 = 15
=> x -105 = 15 . 21
=> x - 105 = 315
=> x = 315 + 105
=> x = 420
h) ( x - 38 ) : 19 = 12
=> x - 38 = 12 . 19
=> x - 38 = 228
=> x = 228 + 38
=> x = 266
i) ( x - 15 ) . ( x - 19 ) = 0
=> x - 15 = 0 => x = 0 + 15 => x = 15
x - 19 = 0 => x = 0 + 19 = x = 19
=> x = 15 ; 19
j) 96 - 3( x + 1 ) = 42
=> 3( x + 1 ) = 96 - 42
=> 3( x + 1 ) = 54
=> x + 1 = 54 : 3
=> x + 1 = 18
=> x = 18 - 1
=> x = 17
a) 15 x 21 - 16 : 4 + 7
= 315 - 4 + 7
= 311 + 7
= 318
b) 123 - 11 x 6 + 150 : 30
= 123 - 66 + 5
= 57 + 5
= 62
Mình chỉ làm đến đó thôi chứ mấy câu còn lại khó hiểu quá!Ở lớp 5 mình chưa học bao giờ.
a)
=315-4+7=318
b)
=123-66+5=62
c)
=2017+5x[300-700:7]
=2017+5x[300-100]
=2017+5x200
=2017+1000
=3017
d)
=1560:[5x79-370+5x21]
=1560:[395-370+105]
=1560:130
=12
e)
=50-[12:2+34]
=50-40
=10
g)
=10-[16x5+88]:28
=10-168:28
=10-6
=4
1a)6,28x18,24+18,24x3,72 d)0,9x95+1,8x2+0,9
=18,24x(6,28+3,72) = 0,9x95+0,9x4+0,9
=18,24x10 =0,9(95+4+1)
=182,4 =0,9x100=90
b) 35,7x99+35+0,7 e)0,25x611,7x40
=35,7x99+35,7 =(0,25x40)x611,7
=35,7x(99+1) =10x611,7
=35,7x100 =6117
=357 g)37,2x101-37-0,2
c)17,34x99+18-0,66 = 101x37,2-(37+0,2)
=17,34x99+17,34 =101x37,2-37,2
=17,34x(99+1) =37,2x(101-1)
=17,34x100 =37,2x100
=1734 =3720
Bạn ơi đăng từng bài thôi mk giải cho. Nhiều quá nhìn hoa mắt mặc dù bài rất dễ!!!
Bài 2:
a, \(\dfrac{5}{23}\) \(\times\) \(\dfrac{17}{26}\) + \(\dfrac{5}{23}\) \(\times\) \(\dfrac{9}{26}\)
= \(\dfrac{5}{23}\) \(\times\) ( \(\dfrac{17}{26}\) + \(\dfrac{9}{26}\))
= \(\dfrac{5}{23}\) \(\times\) \(\dfrac{26}{26}\)
= \(\dfrac{5}{23}\)
b, \(\dfrac{3}{4}\) \(\times\) \(\dfrac{7}{9}\) + \(\dfrac{7}{4}\) \(\times\) \(\dfrac{3}{9}\)
= \(\dfrac{7}{12}\) + \(\dfrac{7}{12}\)
= \(\dfrac{14}{12}\)
= \(\dfrac{7}{6}\)
Bài 3 :
b) Ta có 1+ 2 + 3 +4 + ...+ x =15
Nên \(\frac{x\left(x+1\right)}{2}=15\)
\(x\left(x+1\right)=30\)
=> \(x\left(x+1\right)=5.6\)
=> x = 5
Bài 2:
h; \(\dfrac{2}{3}\)\(x\) + 50% + \(x\) = \(\dfrac{1}{10}\)
\(\dfrac{2}{3}\)\(x\) + \(\dfrac{1}{2}\) + \(x\) = \(\dfrac{1}{10}\)
(\(\dfrac{2}{3}\)\(x\) + \(x\)) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) (\(\dfrac{2}{3}\) + 1) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) + \(\dfrac{1}{2}\) = \(\dfrac{1}{10}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) = \(\dfrac{1}{10}\) - \(\dfrac{1}{2}\)
\(x\) \(\times\) \(\dfrac{5}{3}\) = \(\dfrac{-2}{5}\)
\(x\) = \(\dfrac{-2}{5}\): \(\dfrac{5}{3}\)
\(x\) = - \(\dfrac{6}{25}\)
Lớp 5 chưa học số âm em nhé.
a)320 + ( 218-x)=475
( 218-x)=475-320
( 218-x)=155
x =218-155
x =63
b)315-6/x=275
6/x=315-275
6/x=40
x=40.6
x=240
c)4*(x-15)+32=64
4*(x-15) =64-32
4*(x-15) = 32
4*(x-15) =32:4
4*(x-15) =8
(x-15) =8:4
(x-15) =2
x =2+15
x =17