1, Thực hiện phép tính:
a, -40 + (-37) - (-29)
b, 27 + (-36) - (-45)
c, -125 - [(-18) - 125]
d, 140 + [(-184) - 140]
2, Tìm x biết
a, x - (-15) = -8
b, -40 - x = -35
c, x + (-50) = -27
_Giúp mình vs, mình đang cần gấp lắm í_
Giải
Bài 1
\(1,a,-40-37-\left(-29\right)\\ =-40-37+29\\ =-77+29=-48\\ b,27+\left(-36\right)-\left(-45\right)=27-36+45\\ =-9+45\\ =36\\ c,-125-\left[\left(-18\right)-125\right]\\ =-125+18+125\\ =\left(-125+125\right)+18\\ =18\\ d,140+\left[\left(-184\right)-140\right]\\ =140-184-140\\ =\left(140-140\right)-184\\ =0-184\\ =-184\)
Bài 2
\(a,x-\left(-15\right)=-8\\ =>x+15=-8\\ =>x=-8-15\\ =>x=-23\\ b,-40-x=-35\\ =>x=\left(-40\right)-\left(-35\right)\\ =>x=-40+35\\ =>x=-5\\ c,x+\left(-50\right)=-27\\ =>x-50=-27\\ =>x=-27+50\\ =>x=23\)
1, Thực hiện phép tính:
\(a,-40+\left(-37\right)-\left(-29\right)=-77-\left(-29\right)=-48\)
\(b,27+\left(-36\right)-\left(-45\right)=-9-\left(-45\right)=36\)
\(c,-125-\left[\left(-18\right)-125\right]=-125-\left(-143\right)=18\)
\(d,140+\left[\left(-184\right)-140\right]=140+\left(-324\right)=-184\)
2, Tìm x biết:
\(a,x-\left(-15\right)=-8\)
\(x=-8+\left(-15\right)\)
\(x=-23\)
\(b,-40-x=-35\)
\(x=-40-\left(-35\right)\)
\(x=-5\)
\(c,x+\left(-50\right)=-27\)
\(x=-27-\left(-50\right)\)
\(x=23\)
Bài 1:
a, − 40 − 37 − (− 29)
= − 40 − 37 + 29
= − 77 + 29
= − 48
b, 27 + (− 36) − (− 45)
= 27 − 36 + 45
= − 9 + 45
= 36
c, − 125 − [(− 18) − 125 ]
= − 125 + 18 + 125
= (− 125 + 125) + 18
= 18
d, 140 + [(− 184) − 140]
= 140 − 184 − 140
Bài 1 Thực hiện phép tính
a. 369 – (|- 206| – 15) – (- 206 + |- 369|)
b. 345 – 150 : [(33 – 24)2 – (– 21)] + 20160
c. – 2 + 6 – 12 + 16 – 22 + 26 –…– 92 + 96
Bài 2 Tìm x ∈ Z biết:
a. 20 – [42 + (x – 6)] = 90
b. 24 – |x + 8| = 3.(25 – 52)
c. 1000 : [30 + (2x – 6)] = 32 + 42 và x ∈ N
d. (x + 11) ⋮ (x + 2) và x ∈ N
Bai 1 : Tinh a) 24 - (-15) - 2 b) (-85) + 10 - (-85) - 50 c) 71 - (-30) - (+18) + (-30)
d) -(30) - (+37) + (+37) + (-85) e) (35-815) - (795-65) g) (2002-79+15) + (-79+15)
h) -(515-80+91) - (2003+80-91)
Bai 2: Tim x,biet a) 25 - (30+x) = x - (27-8) b) (x-12) - 15 = (20-17) - (18+x) c) 15 - x = 7 - (-2) d) x - 35 = (-12) - 3 e) I5-xI - 26 = - 15
Bài 1:
a) \(24 - (-15) - 2\)
\(=39-2\)
\(=37\)
b) \((-85) + 10 - (-85) - 50\)
\(=[(-85)-(-85)]+10-50\)
\(=0+10-50\)
\(=10-50\)
\(=-40\)
c) \(71 - (-30) - (+18) + (-30)\)
\(=[(-30)-(-30)]+71-(+18)\)
\(=0+71-18\)
\(=71-18\)
\(=53\)
d) \(-(30) - (+37) + (+37) + (-85)\)
\(=[-(+37)+(+37)]-(30)+(-85)\)
\(=0-(30)+(-85)\)
\(=(-30)+(-85)\)
\(=-115\)
e) \((35-815) - (795-65)\)
\(=(-780)-730\)
\(=-1510\)
g) \((2002-79+15) + (-79+15)\)
\(=1938+(-64)\)
\(=1874\)
Bài 2:
a) \(25 - (30+x) = x - (27-8)\)
\(25-30-x=x-27+8\)
\(x+x=25-30+27-8\)
\(2x=14\)
\(x=14\div2\)
\(x=7\)
b) \((x-12) - 15 = (20-17) - (18+x) \)
\(x-12-15=13-18-x\)
\(x-27=-5-x\)
\(x+x=-5+27\)
\(2x=22\)
\(x=22\div2\)
\(x=11\)
c) \(15 - x = 7 - (-2)\)
\(15-x=9\)
\(x=15-9\)
\(x=6\)
d) \(x - 35 = (-12) - 3\)
\(x-35=-15\)
\(x=-15+35\)
\(x=20\)
e) \(\left|5-x\right|-26=-15\)
\(\left|5-x\right|=-15+26\)
\(\left|5-x\right|=11\)
Từ đây ta có:
*Nếu \(5-x=11\)
\(x=5-11\)
\(x=-6\)
*Nếu \(5-x=-11\)
\(x=5-(-11)\)
\(x=16\)
Vậy \(x=-6;x=16\)
1tính
a) (-6-18 ) : (-4)
b) -28 . (50-42 ) - 35 . ( 34 - 62 )
c) -18 - (-5) + 26
d) -72 . 69 + 31 . (-72)
e) 7 . (-6)2 + ( -42) .17
f) (-38+45 ). ( -36)
2 tìm x
a) x + 49 = 17
b) 18-3x=-15
c) (x-5)=2
d) 15-3(x-2)=-6
e) 36-(18+x)=55
f) -4 |x|=-12
a)(-6-18):(-4)
= { (-6) + (-8) } : (-4)
=(-24) : (-4)= (-6)
b)-28.(50-42)-35.(34-62)
= -28.8-35.(-28)
= -28.(8-35)
= -28.(-27)=756
c)-18-(-5)+26
= -18+5+26
= -13+26=13
d)-72.69+31.(-72)
= -72.(69+31)
= -72.100=-7200
Bài 1: Tính tổng sau một cách hợp lí:
a) 21538589085 b) 91741765
c) 3126201735
d) 5437105467
e) 3264317457 f) 351875125149
g) 4182181181312017 h) 271217...5257
i) 3029...484950
Bài 2: Rút gọn các biểu thức sau:
a) 712435Axxx
b) 341523Bxxx
c) 1525Cxx
Bài 3: Tìm số nguyên x, biết:
a) 31396911x b) 1293555x
c) 377127x d) 1464x
e) 43921315315x f) 743x
g) 151275xxx
h) 57422313472532xxx
Bài 4: Tính tổng sau một cách hợp lí:
a) 71051557105355 b) 3581579565
c) 519720152015 d) 45671234456766
e) 20041554200454 f) 457893574578957
g) 125914091212591409
h) 27501229275043829438
i) 5374515137151 k) 5314535953145259
l) 8113254718113253 m) 50201650118201618
n) 2544975254175549
p) 1735361732929526
q) 171171223172105172223
Bài 5: Tìm số nguyên x, biết:
a) 2525124265x b) 539x
c) 311718x d) 2513xxx
e) 1530278xx f) 334124.84.8x
g) 3119310.2448x
h) 10.251:323x
i) 12152017xx k) 121321x
l) 869x
m) 372041252.5x
Bài 6 : Thực hiện phép tính.
a) 27 . 75 + 25 . 27 - 150; b) 142 - [50 - (23 .10 - 23 .5)]
c) 375 : {32 – [ 4 + (5. 32 – 42)]} – 14 d) {210 : [16 + 3.(6 + 3. 22 )]} – 3
e) 500 – {5[409 – (2³.3 – 21)²] - 1724}
Bài toán 7 : Thực hiện phép tính.
a) 80 - (4.52 - 3.23 ) b) 56 : 54 + 23 .22 – 12017
c) 125 - 2.[56 - 48 : (15 - 7)] d) 23.75 + 25.10 + 25.13 + 180
e) 2448: [119 -(23 -6)] f) [36.4 - 4.(82 - 7.11)2 : 4 – 20160
g) 303 - 3.{[655 - (18 : 2 + 1).43 + 5]} : 100
Bài toán 8 : Tìm x, biết.
a) 48 - 3(x + 5) = 24 e) 4x + 18 : 2 = 13
b) 2x+1 - 2x = 32 g) 2x - 20 = 35 : 33
c) (15 + x) : 3 = 315 : 312 h) 525.5x-1 = 525
d) 250 - 10(24 - 3x) : 15 = 244 k) x - 48 : 16 = 37
Bài toán 9 : Tìm x, biết.
a) [(8x - 12) : 4] . 33 = 36 g) 52x – 3 – 2 . 52 = 52 . 3
b) 41 - 2x+1 = 9 h) 52x – 3 – 2 . 52 = 52 . 3
c) 32x-4 - x 0 = 8 k) 30 - [4(x - 2) + 15] = 3
d) 65 - 4x+2 = 20140 l) 740:(x + 10) = 102 – 2.13
e) 120 + 2.(3x - 17) = 214 m) [(6x - 39) : 7].4 = 12
Bài 1
a, ( -13 ) + ( -37 ) / b, (-45 ) +12 / c, 28 + (-15 ) / d 16 - ( -30)
e, (-24 ) - 9 / f (-42) - 12 / g (-21 ) - (-50) / h 18 - 29
i , - 48 - 72 / k 98 . ( - 2) / l ( -36 ) .3 / m ( -25 ) . (- 4)
a)=-50
b)=-33
c)=13
d)=46
e)=-33
f)=-54
g)=29
h)=-11
i)=-120
k)=-196
l)=-108
m)=100
a)=-50
b)=-33
c)=13
d)=46
e)=-33
f)=-54
g)=29
h)=-11
i)=-120
k)=-196
l)=-108
m)=100
Bài 1:Thực hiện phép tính
a)73+86+968+914+3032
b)341.67+341.16+659.83
c)252-84:21+7
d)4.8.25.125.27
e)34+35+36+37-24-25-26-27
g)1-2+3-4+...-98+99
h)1-4+7-10+...-100+103
Bài 2:Tìm số nguyên x,biết:
l)3636:(12.x-91)=36
m)(x:23+45).67=8911
n)[(6.x-39):7].4=12
p)128-3(x+4)=23
q)[(4.x+28).3+55]:5=35
r)123-5.(x+4)=38
t)11-(53+x)=97
i)23.75+25.23+180
a)73+86+968+914+3032
= (86 + 914) +(968 + 3032) + 73
= 1000 + 4000 + 73
= 5073
b)341.67+341.16+659.83
=341 (67 + 16) + 659 * 83
= 341 * 83 + 659 * 83
= (341+ 659) * 83
= 1000 * 83
= 830000
c)252-84:21+7
= 252 - 2 +7
=257
d)4.8.25.125.27
= (8 * 125) (4* 25) * 27
= 1000 * 100 * 27
= 2700000
e)34+35+36+37-24-25-26-27
= (34-24) + (35-25) + (36-26) + (37-27)
= 10 + 10 + 10 + 10
= 40
g)1-2+3-4+...-98+99
= (1 + 99) + (-2-98) + .....+ (-48 - 52) + (49 + 51) - 50
= 100 - 50
= 50
h)1-4+7-10+...-100+103
Bài 2:Tìm số nguyên x,biết:
l)3636:(12.x-91)=36
3636 : (12x - 91) = 36
12x - 91 = 101
12x = 192
x= 16
m)(x:23+45).67=8911
x: 23 + 45 = 133
x : 23 = 88
x= 88/23
n)[(6.x-39):7].4=12
6x - 39 = 3
6x = 42
x=7
p)128-3(x+4)=23
3(x+4) = 105
x+4= 35
x= 31
q)[(4.x+28).3+55]:5=35
(4x + 28)*3 +55 = 175
(4x + 28) * 3 = 120
4x + 28 = 40
4x = 12
x=3
r)123-5.(x+4)=38
5(x+4) = 85
x+4 = 17
x= 13
t)11-(53+x)=97
53 + x = -86
x= -139
i)23.75+25.23+180
= 23(75+25) + 180
= 2300 + 180
= 2480
https://friend20.com/vn/d20/quiz/69707687
Tìm số tự nhiên x biết
a) (x + 30) – 75 = 125
b) x – 72 : 36 = 18
c) x – 17 = 54
d) 36 – (x – 2) = 12
e) 9x – 7 = 837
f) (x – 15) – 107 = 0
g) 134 + (116 – x) = 145
a, (x + 30) – 75 = 125
=> x + 30 = 125 + 75 = 200
=> x = 200 – 30
=> x = 170
Vậy x = 170
b, x – 72 : 36 = 18
=> x – 2 = 18
=> x = 18 + 2 = 20
Vậy x = 20
c, x – 17 = 54
=> x = 54 +17
=> x = 71.
Vậy x = 71
d, 36 – (x – 2) = 12
=> x – 2 = 36 – 12
=> x = 24 + 2 = 26
Vậy x = 26
e, 9x – 7 = 837
=>9x = 837 + 7 = 844
=> x = 844 9
Vậy x = 844 9
f, (x – 15) – 107 = 0
=> x – 15 = 107
=> x = 107 +15
=> x = 122.
Vậy x = 122
g, 134 + (116 – x) = 145
=> 116 – x = 145 – 134
=> x = 116 – 11
=> x = 5.
Vậy x = 5
TL
a) 5x + 20 = 110
<=> x = 90 : 5 = 18
b) x + 18 = - 13
<=> x = - 31
c) 120 - x = 50
<=> x = 70
d) 10 - x = -29
<=> x = 39
e) - x + 31 = 61
<=> x = -30
f) -85 - x = --70
<=> x = 15
Khi nào rảnh vào kênh H-EDITOR xem vid nha!!! Thanks!
