86-x>86-4
x+28<28+3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 86 - x < 86 - 4
86 - x < 82
x < 86 - 82
x < 4
b) hình như đề bài sai hay sao á
\(28.\left(14+86\right)-120\)
\(28.100-120=2800-120=2680\)
14 x 28 + 28 x 86 - 120
= 28 x ( 14 + 86 ) - 120
= 28 x 100 - 120 = 2800 - 120
= 2680
1) Ta có: \(\left(-86-x\right)-\left(3+2x\right)=-4-15\)
\(\Leftrightarrow-86-x-3-2x+4+15=0\)
\(\Leftrightarrow-3x-70=0\)
\(\Leftrightarrow-3x=70\)
hay \(x=-\dfrac{70}{3}\)
Vậy: \(x=-\dfrac{70}{3}\)
2) Ta có: \(18+\left(-x\right)-\left(40-28\right)=-32-\left(-18\right)\)
\(\Leftrightarrow18-x-40+28+32-18=0\)
\(\Leftrightarrow-x+20=0\)
\(\Leftrightarrow-x=-20\)
hay x=20
Vậy: x=20
3) Ta có: \(-27-\left(-31+x\right)-25=-5-17\)
\(\Leftrightarrow-27+31-x-25+5+17=0\)
\(\Leftrightarrow-x+1=0\)
\(\Leftrightarrow-x=-1\)
hay x=1
Vậy: x=1
4) Ta có: \(-9-14-x+42-38=-5+13\)
\(\Leftrightarrow-x-19=8\)
\(\Leftrightarrow-x=27\)
hay x=-27
Vậy: x=-27
\(42.15-28.15+86.15\)
= \(\left(42-28+86\right).15\)
= \(100.15\)
= \(1500\)
Chúc bạn học tốt !!!
\(37\times46+37\times51+111\)
\(=37\times46+37\times51+37\times3\)
\(=37\times\left(46+51+3\right)\)
\(=37\times100\)
\(=3700\)
------------
\(172\times47+86\times8-34\times4\)
\(=172\times47+172\times4-34\times4\)
\(=172\times\left(47+4\right)-34\times4\)
\(=172\times51-34\times4\)
\(=172\times3\times17-17\times2\times4\)
\(=17\times\left(172\times3-2\times4\right)\)
\(=17\times\left(516-8\right)\)
\(=17\times508\)
\(=8636\)
------------
\(35\times215-35\times200-175\)
\(=35\times215-35\times200-35\times5\)
\(=35\times\left(215-200-5\right)\)
\(=35\times10\)
\(=350\)
------------
\(48\times56+28\times104\)
\(=48\times2\times28+28\times104\)
\(=28\times\left(48\times2+104\right)\)
\(=28\times200\)
\(=5600\)
a) Ta có : ( x + 1 ).( 3 - x ) > 0
Th1 : \(\hept{\begin{cases}x+1>0\\3-x>0\end{cases}\Rightarrow\hept{\begin{cases}x>-1\\x>3\end{cases}\Rightarrow}x>3}\)
Th2 : \(\hept{\begin{cases}x+1< 0\\3-x< 0\end{cases}\Rightarrow\hept{\begin{cases}x< -1\\x< 3\end{cases}\Rightarrow}x< -1}\)
a) \(86+375+14\)
\(=\left(86+14\right)+375\)
\(=100+375\)
\(=475\)
b) \(72+69+128\)
\(=\left(72+128\right)+69\)
\(=200+69\)
\(=269\)
c) \(25\cdot5\cdot4\cdot27\cdot2\)
\(=\left(25\cdot4\right)\cdot\left(5\cdot27\right)\cdot2\)
\(=100\cdot135\cdot20\)
\(=200\cdot135\)
\(=27000\)
d) \(28\cdot64+28\cdot36\)
\(=28\cdot\left(64+36\right)\)
\(=28\cdot100\)
\(=2800\)
a: 86-x>86-4
=>-x>-4
hay x<4
b: x+28<28+3
=>x+28<31
hay x<3
x=0,1,2,3
x=0,1,2