![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 2x + 25 = 145
\(\Rightarrow\)2x = 145 - 25
\(\Rightarrow\)2x = 120
\(\Rightarrow\)x = 60
b) 216 : x + 34 : x = 10
\(\Rightarrow\)( 216 + 34) : x = 10
\(\Rightarrow\)250 : x = 10
\(\Rightarrow\)x = 250 : 10
\(\Rightarrow\)x = 25
c) 2017 : x - 17 : x = 1000
\(\Rightarrow\)( 2017 - 17 ) : x = 1000
\(\Rightarrow\)2000 : x = 1000
\(\Rightarrow\)x = 2000 : 1000
\(\Rightarrow\)x = 2
d) 4057 + (2x : 38 ) = 20395
\(\Rightarrow\)2x : 38 = 20395 - 4057
\(\Rightarrow\)2x : 38 = 16338
\(\Rightarrow\)2x = 16338 . 38
\(\Rightarrow\)2x = 620844
\(\Rightarrow\)x = 620844 : 2
\(\Rightarrow\)x = 310422
e) ( x + 1 ) + ( x + 4 ) + ( x + 7 ) + ... + ( x + 28 ) = 155 ( có 10 số hạng x )
\(\Rightarrow\)x + 1 + x + 4 + x + 7 + ... + x + 28 = 155
\(\Rightarrow\)10x + ( 1 + 4 + 7 + ... + 28 ) = 155
\(\Rightarrow\)10x + 145 = 155
\(\Rightarrow\)10x = 155 - 145
\(\Rightarrow\)10x = 10
\(\Rightarrow\)x = 1
![](https://rs.olm.vn/images/avt/0.png?1311)
a: \(B=\dfrac{154}{155+156}+\dfrac{155}{155+156}\)
\(\dfrac{154}{155}>\dfrac{154}{155+156}\)
\(\dfrac{155}{156}>\dfrac{155}{155+156}\)
=>154/155+155/156>(154+155)/(155+156)
=>A>B
b: \(C=\dfrac{2021+2022+2023}{2022+2023+2024}=\dfrac{2021}{6069}+\dfrac{2022}{6069}+\dfrac{2023}{6069}\)
2021/2022>2021/6069
2022/2023>2022/2069
2023/2024>2023/6069
=>D>C
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(-75+\left(-325\right)+\left|-45\right|-\left(-125\right)\)
\(=-75-325+45+125\)
\(=\left(45+125\right)-\left(75+325\right)\)
\(=170-400\)
\(=-230\)
b) \(62+\left|128\right|-\left|-155\right|-\left|70\right|\)
\(=62+128-155-70\)
\(\Leftrightarrow190-225\)
\(=-35\)
c) \(815+\left[95+\left(-815\right)+\left(-45\right)\right]\)
\(=815+95-815-45\)
\(=\left(815-815\right)+\left(95-45\right)\)
\(=0+50\)
\(=50\)
d) \(5+\left(-7\right)+9+\left(-11\right)+...+25+\left(-27\right)\)
\(=\left(5-7\right)+\left(9-11\right)+...+\left(25-27\right)\)
\(=-2-2-...-2\)
\(=-2.11\)
\(=-22\)
e) \(34+35+36+37-24-25-26-27\)
\(=\left(34-24\right)+\left(35-25\right)+\left(36-26\right)+\left(37-27\right)\)
\(=10+10+10+10\)
\(=40\)
![](https://rs.olm.vn/images/avt/0.png?1311)
1045 + 57 - 1045 - 67
= ( 1045 - 1045 ) + ( 57 - 67 ) [_Tự lm tiếp_]
1890 - 456 - 434
= 1890 - ( 456 + 434 )
= 1890 - 890 [_Tự lm tiếp_]
-45 + 189 - 155
= 189 - ( 45 + 155 )
= 189 - 200 [_Tự lm tiếp_]
-127 + 34 - 73 + 166
= ( -127 + -73 ) + ( 34 + 166 ) [_Tự lm tiếp_]
-15 - 17 + 29 + 15 - 83
= ( -15 + 15 ) - ( 17 - 29 + 83 ) [_Tự lm tiếp_]
-45 + 140 - (-45) - 240
= [ -45 - ( -45 ) ] + ( 140 - 240 ) [_Tự lm tiếp_]
-75 + (-89) + (-75) + 89 - 122
= [ -75 + ( -75 ) ] + [ ( -89 ) + 89 ] - 122 [_Tự lm tiếp_]
P/s: Hoq chắc_:333
![](https://rs.olm.vn/images/avt/0.png?1311)
155 . 155 -155 . 41 : 114
= 155( 155-41):114
=155.114:114
=155
(7256.4375 - 725)/(3650 + 4375.7255)
= [(7255 +1).4375 - 725]/(3650 + 4375.7255)
= [(7255.4375 + 1.4375 - 725]/(3650 + 4375.7255)
= (7255.4375 + 3650)/(3650 + 4375.7255) = 1
a) (155.155-155.41):114
= 155( 155-41):114
=155.114:114
=155
(7256.4375 - 725)/(3650 + 4375.7255)
= [(7255 +1).4375 - 725]/(3650 + 4375.7255)
= [(7255.4375 + 1.4375 - 725]/(3650 + 4375.7255)
= (7255.4375 + 3650)/(3650 + 4375.7255) = 1
![](https://rs.olm.vn/images/avt/0.png?1311)
a, x= 155 -51 <=> x=104
b.x=-120 : -24 <=> x=5
c.2(81-x)= 155 -35
<=> 2(81-x)=120
<=> 81 - x = 60
<=> x= 21
Lời giải:
a.
$155-x=51$
$x=155-51=104$
b.
$(-24)x=-120$
$x=(-120):(-24)=5$
c.
$35+2(81-x)=155$
$2(81-x)=155-35=120$
$81-x=120:2=60$
$x=81-60=21$
![](https://rs.olm.vn/images/avt/0.png?1311)
1. a, (8576 + (-536)) - 8576
= 8576 - 536 - 8576
= -536
b, (-7105) - (155 - 7105)
= -7105 - 155 + 7105
= -155
c,-8715+ (1345 + 8715)
= -8715 + 1345 + 8715
= 1345
d,(35 - 815) - (795 - 65)
= 35 - 815 - 795 + 65
= ( 35 + 65 ) + (-815 - 795)
= 100 - 1610
= -1510
e,f, bạn làm tương tự nhé!
Bài 2:a, / a - 2/ = 0
a - 2 = 0
a = 2
b, bạn ghi sai đề rồi
\(a)34+11x=155\\<=>11x=155-34\\<=>11x=121\\<=>x=11\)