Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1: x=7+5=12
2: =>-29-x=-10
=>x+29=10
=>x=-19
3: =>x+7=-18
=>x=-25
4: =>x+19-11=0
=>x+8=0
=>x=-8
a, 71.2 – 6.(2x+5) = 10 5 : 10 3
71.2 – 6.(2x+5) = 10 2
6.(2x+5) = 71.2 – 100
6.(2x+5) = 42
x = 1
b, 5 x + 3 4 . 6 8 = 6 9 . 3 4
5 x + 3 4 . 6 8 = 6 8 . 6 . 3 4
5 x + 3 4 = 6 8 . 6 . 3 4 : 6 8 = 6 . 3 4
5x = 6 . 3 4 - 3 4 = 5 . 3 4
x = 3 4
c, 12:{390:[5. 10 2 – ( 5 3 + x . 7 2 )]} = 4
390:[5. 10 2 – ( 5 3 + x . 7 2 )] = 12:4 = 3
5. 10 2 – ( 5 3 + x . 7 2 ) = 390:3 = 130
5 3 + x . 7 2 = 5. 10 2 – 130 = 370
x . 7 2 = 370 – 5 3 = 245
x = 245: 7 2 = 5
d, 5 3 .(3x+2):13 = 10 3 : 13 5 : 13 4
5 3 .(3x+2):13 = 10 3 : 13
3x+2 = 10 3 : 13 : 5 3 .13 = 8
x = 2
\(2436\cdot\left(5\cdot x+103\right)=12\)
\(5\cdot x+103=2436:12=203\)
\(5\cdot x=203-103=100\)
\(x=100:5=20\)
\(2436.\left(5x+103\right)=12\)
\(5x+103=12:2436\)
\(5x+103=12:2436\)
\(5x+103=\frac{1}{2003}\)
\(5x=\frac{1}{2003}-103\)
\(5x=\frac{-206308}{2003}\)
\(x=\frac{-206308}{2003}.\frac{1}{5}\)
\(x=\frac{-206308}{10015}\)
Vì x chia 6 dư 3; chia 8 dư 5; chia 12 dư 9
=> x-3 chia hết cho 6;8;12
=> x-3 \(\in\) BC(6;8;12) = {0;24;48;72;96;120;...;240;264;288;312;...}
=> x \(\in\) {3;27;51;75;...;243;267;291;315;...}
Mà 264 <x\(\le\) 300 => x \(\in\) {267;291}
Ta có \(131x-941=16\)
\(\Rightarrow131x=957\)
\(\Rightarrow x=\frac{957}{131}\)
b.\(12.\left(x-1\right):3=103\)
\(\Rightarrow12.\left(x-1\right)=309\)
\(\Rightarrow x-1=\frac{103}{4}\)
\(\Rightarrow x=\frac{107}{4}\)
264+12x=1800
12x=1536
x=128
(x+73):19=321
x+73=6099
x=6026
2x+3x+4x=18
9x=18
x=2
10<2x<20
=>5<x<10
x=6,7,8,9
\(264+12x=1800\)
\(\Leftrightarrow12x=1536\)
\(\Leftrightarrow x=128\)
==============
\(\left(x+73\right):19=321\)
\(\Leftrightarrow x+73=6099\)
\(\Leftrightarrow x=6026\)
===============
\(2x+3x+4x=18\)
\(\Leftrightarrow x.\left(2+3+4\right)=18\)
\(\Leftrightarrow x.9=18\)
\(\Leftrightarrow x=2\)
================
\(10< 2x< 20\)
..................................
\(2x=12\Leftrightarrow x=6\)
\(2x=14\Leftrightarrow x=7\)
\(2x=16\Leftrightarrow x=8\)
\(2x=18\Leftrightarrow x=9\)
\(x\in\left\{6;7;8;9\right\}\)
12x = 1800 - 264
12x = 1536
x = 1536 : 12
x = 128
( x + 73 ) : 19 = 321
( x + 73 ) = 321 x 19
x + 73 = 6099
x = 6099 - 73
x = 6026
2x + 3x + 4x = 18
x . ( 2 + 3 + 4 ) = 18
x . 9 = 18
x = 18 : 9
x = 2
10 < 2x < 20
x = 6 ; 7 ; 8 ; 9