tìm x bít
1 | 3x - 18 | = 45
2 |19 + x + 95| = 190
tìm x biết
1 | 3x - 18 | = 45
2 |19 + x + 95| = 190
tìm x biết
1 | 3x - 18 | = 45
2 |19 + x + 95| = 190
Ta có \(\left|3x-18\right|=45\Rightarrow\orbr{\begin{cases}3x-18=-45\\3x-18=45\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}3x=-27\\3x=63\end{cases}\Rightarrow\orbr{\begin{cases}x=-9\\x=21\end{cases}}}\)
Vậy ..........
2,\(\left|19+x+95\right|=190\Rightarrow\left|x+114\right|=190\)
\(\Rightarrow\orbr{\begin{cases}x+114=190\\x+114=-190\end{cases}\Rightarrow\orbr{\begin{cases}x=76\\x=-304\end{cases}}}\)
Vậy......
TK MK NHA
tìm x:a.1+(1+2x)+(1+3x)+...+(1+19x)=417
b.10+(11+x)+(12+2x)+(13+3x)+...+(19+9x)=190
câu 1:
a) 500-(300)-190+(-210)
b) (-3)3 .5+12.(-6)
c) 15.(-19-4)-19.(15-4)
câu 2: tìm x thuộc Z
a) 3x-2=3
b) x chia hết cho 5 và -7<x<11
câu 1:
a) 500-(300)-190+(-210)
= 500-300-190-210
= 200 - 210 -190
=-10 - 190
=-200
b) (-3)3 .5+12.(-6)
= -27.5 -72
=-135 - 72
=-207
c) 15.(-19-4)-19.(15-4)
= 15.(-23) - 19.11
=-345 - 209
=-554
câu 2: tìm x thuộc Z
a) 3x-2=3
=> 3x=3/2
=> x=1/2
b) x chia hết cho 5 và -7<x<11
=> x thuộc {-5;0;5;10}
Câu 1:
a) Ta có: \(500-\left(300\right)-190+\left(-210\right)\)
\(=500-300-190-210\)
\(=\left(500-300\right)-\left(190+210\right)\)
\(=200-400=-200\)
b) Ta có: \(\left(-3\right)^3\cdot5+12\cdot\left(-6\right)\)
\(=\left(-3\right)^3\cdot5-3\cdot4\cdot3\cdot2\)
\(=-5\cdot3^3-3^2\cdot8\)
\(=3^2\cdot\left(-5\cdot3-8\right)\)
\(=9\cdot\left(-15-8\right)=9\cdot\left(-23\right)=-207\)
c) Ta có: \(15\cdot\left(-19-4\right)-19\cdot\left(15-4\right)\)
\(=-15\cdot19-15\cdot4-15\cdot19+19\cdot4\)
\(=-30\cdot19+4\cdot4\)
\(=-2\cdot\left(15\cdot19+2\cdot4\right)\)
\(=-2\cdot\left(285+8\right)=-586\)
1, Tính nhanh nếu có thể:
a) 18 - 10 : 2 - 7
b) ( 6 . 8 - 10 : 5 ) + 3 . ( -7)
c) -8 . 25 . ( -2) - 4 . ( -5)
d) 19 . 25 - 19 . 95 - 19 . 20
e) -256 . 43 - 256 . 25 - 256 . 32
g) -159 . 56 + 43 . ( -159 )
h) 29 . ( 19 - 13 ) - 19 . ( 29 - 13 )
2, Tìm x:
a) -3x + 6 = -9
b) 10 - 2x = 20 - 4x
c) ( x + 5 ) . ( x + 4 ) = 0
d) ( -2x - 10 ) . ( 3x + 18 ) = 0
e) ( x - 1 ) . ( x + 2 ) . ( -x - 3 ) = 0
3, Cho: A = 1 - 2 + 22 - 23 + ... - 22015 + 22016
a) Tính A
b) Tìm x , biết: 3A - 1 = 2
a)=18-5-7
=13-7
=5
b)=(48-2)+(-21)
46+(-21)
=25
c)=-200.(-2)+20
=400+20=420
Tìm x :
a.12 + x + (-5) = -18 - 2x
b.(-14) - x + (-15) = -10 + (4 - 2x)
c.x - (-19) - (-11) = -(3x + 40)
a) \(12+x+\left(-5\right)=-18-2x\)
\(\Rightarrow12+x-5=-18-2x\)
\(\Rightarrow x+7+18+2x=0\)
\(\Rightarrow3x=-25\)
\(\Rightarrow x=-\dfrac{25}{3}\)
b) \(\left(-14\right)-x+\left(-15\right)=-10+\left(4-2x\right)\)
\(\Rightarrow-14-x-15=-10+4-2x\)
\(\Rightarrow-x-29=-2x-6\)
\(\Rightarrow-x+2x=-6+29\)
\(\Rightarrow x=23\)
c) \(x-\left(-19\right)-\left(-11\right)=-\left(3x+40\right)\)
\(\Rightarrow x+19+11=-3x-40\)
\(\Rightarrow x+30=-3x-40\)
\(\Rightarrow x+3x=-40-30\)
\(\Rightarrow4x=-70\)
\(\Rightarrow x=-\dfrac{35}{2}\)
Tìm x biết
2x + 19 + x = 190
\(2x+19+x=190\)
\(2x+x=190-19\)
\(2x+x=171\)
\(2x+1x=171\)
\(\left(2+1\right)x=171\)
\(3x=171\)
\(x=171:3\)
\(x=57\)
2x+19+x=190
2x+x=190-19
3x=171
x=171:3
x=57
Vậy x=57
Cảm ơn các bạn rất nhiều
bài 19: tìm x
c) ( 34 - 2x ) . ( 2x - 6 ) = 0
d) ( 2019 - x ) . ( 3x - 12 ) 0
e) 57 . ( 9x - 27 ) = 0
f) 25 + ( 15 - x ) = 30
g) 43 - ( 24 - x ) = 20
h) 2 . ( x - 5 ) - 17 = 25
i) 3 . ( x + 7 ) - 15 = 27
j) 15 + 4 . ( x - 2 ) = 95
k) 20 - ( x + 14 ) = 5
l) 14 + 3 . ( 5 - x ) = 27
nhanh nha, mik tick cho, ccau trình bày dễ hiểu, ko cần ''hoặc''
`@` `\text {Ans}`
`\downarrow`
`c)`
`( 34 - 2x ) . ( 2x - 6 ) = 0`
`=>`\(\left[{}\begin{matrix}34-2x=0\\2x-6=0\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}2x=34\\2x=6\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=34\div2\\x=6\div2\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=17\\x=3\end{matrix}\right.\)
Vậy, `x \in {17; 3}`
`d)`
`( 2019 - x ) . ( 3x - 12 ) =0` `?`
`=>`\(\left[{}\begin{matrix}2019-x=0\\3x-12=0\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019-0\\3x=12\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019\\x=12\div3\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=2019\\x=4\end{matrix}\right.\)
Vậy, `x \in {2019; 4}`
`e) `
`57 . ( 9x - 27 ) = 0`
`=>`\(9x-27=0\div57\)
`=> 9x - 27 = 0`
`=> 9x = 27`
`=> x = 27 \div 9`
`=> x = 3`
Vậy, `x = 3`
`f)`
`25 + ( 15 - x ) = 30`
`=> 15 - x = 30 - 25`
`=> 15 - x = 5`
`=> x = 15 -5 `
`=> x = 10`
Vậy, `x = 10`
`g) `
`43 - ( 24 - x ) = 20`
`=> 24 - x = 43 - 20`
`=> 24 - x = 23`
`=> x = 24 - 23`
`=> x = 1`
Vậy, `x = 1`
`h) `
`2 . ( x - 5 ) - 17 = 25`
`=> 2 ( x - 5) = 25+17`
`=> 2 ( x - 5) = 42`
`=> x - 5 = 42 \div 2`
`=> x - 5 = 21`
`=> x = 21 + 5`
`=> x = 26`
Vậy, `x = 26`
`i)`
`3 . ( x + 7 ) - 15 = 27`
`=> 3(x + 7) = 27 + 15`
`=> 3(x + 7) = 42`
`=> x +7 = 42 \div 3`
`=> x + 7 = 14`
`=> x = 14 - 7`
`=> x = 7`
Vậy, `x = 7`
`j)`
`15 + 4 . ( x - 2 ) = 95`
`=> 4(x - 2) = 95 - 15`
`=> 4(x - 2) = 80`
`=> x - 2 = 80 \div 4`
`=> x - 2 = 20`
`=> x = 20 + 2`
`=> x = 22`
Vậy, `x = 22`
`k)`
`20 - ( x + 14 ) = 5`
`=> x + 14 = 20 - 5`
`=> x + 14 = 15`
`=> x = 15 - 14`
`=> x = 1`
Vậy, `x = 1`
`l) `
`14 + 3 . ( 5 - x ) = 27`
`=> 3(5 - x) = 27 - 14`
`=> 3(5 - x) = 13`
`=> 5 - x = 13 \div 3`
`=> 5 - x = 13/3`
`=> x = 5- 13/3`
`=> x = 2/3`
Vậy, `x = 2/3.`
`@` `\text {Kaizuu lv uuu}`
Giải hộ:
-452-(-67+75-452)
35-{12-[-14+(-2)]}
-|-5|+(-19)+18+|11-4|-57
1) \(-452-\left(-67+75-452\right)\)
\(=-452+67-75+452\)
\(=-\left(452-67\right)-75+452\)
\(=-385-75+452\)
\(=-\left(385+75\right)+452\)
\(=-460+452\)
\(=-\left(460-452\right)\)
\(=-8\)
b) \(35-\left\{12-\left[-14+\left(-2\right)\right]\right\}\)
\(=35-\left[12-\left(-14-2\right)\right]\)
\(=35-\left\{12-\left[-\left(14+2\right)\right]\right\}\)
\(=35-\left[12-\left(-16\right)\right]\)
\(=35-\left(12+16\right)\)
\(=35-28\)
\(=7\)
c) \(-\left|-5\right|+\left(-19\right)+18+\left|11-4\right|-57\)
\(=-5-19+18+\left|7\right|-57\)
\(=-5-19+18+7-57\)
\(=-\left(5+19\right)+18+7-57\)
\(=-24+18+7-57\)
\(=-\left(24-18\right)+7-57\)
\(=-6+7-57\)
\(=-\left(6-7\right)-57\)
\(=-\left(-1\right)-57\)
\(=1-57\)
\(=-57+1\)
\(=-\left(57-1\right)\)
\(=-56\)
Mình đặt tên a,b,c cho 3 ý cho dễ gọi nha.
a,\(-452-\left(-67+75-452\right)\)
\(=-452+67-75+452\)
\(=-8\)
b,\(35-\left\{12-\left[-14+\left(-2\right)\right]\right\}\)
\(=35-\left(12+14-2\right)\)
\(=35-24\)
\(=11\)
c,\(-\left|-5\right|+\left(-19\right)+18+\left|11-4\right|-57\)
\(=-5-19+18+7-57\)
\(=-56\)