giai rgiups mình
a, 798 + 100 : [ 19 - 2 . [ 52 - 22 ]2
b, 921 . 172 . 13 - 921 . 85
c, 52 . [52 - 3 ] : 11] - 16 + 2 . 15
Thực hiện phép tính:
a, 36:{336:[200–(12+8.20)]}
b, {145–[130–(246–236)]:2}.5
c, 100:{250:[450–(4. 5 3 – 2 2 .25]}
d, 798+100:[16–2.( 5 2 –22)]
e, (6954+1525:5+47.19).(29–58.2)
f, 2 4 .157– 2 4 .58+16
a, 36:{336:[200–(12+8.20)]}
= 36:{336:[200–(12+160)]}
= 36:{336:[200–172]}
= 36:{336:28}
= 36:12 = 3
b, {145–[130–(246–236)]:2}.5
= {145–[130–10:2]}.5
= {145–130}.5
= 20.5 = 100
c, 100:{250:[450–(4. 5 3 – 2 2 .25]}
= 100:{250:[450–400]}
= 100:{250:50}
= 100:5 = 20
d, 798+100:[16–2.( 5 2 –22)]
= 798+100:10
= 798+10 = 808
e, (6954+1525:5+47.19).(29–58.2)
= (6954+1525:5+47.19).0 = 0
f, 2 4 .157– 2 4 .58+16
= 16.(157–58+1) = 1600
Giúp mình với nha
Bài 3. Tính hợp lý :
1) 84 + 245 + 16 2) 467 + 238 + 533 + 762 + 3465 3) 1 + 3 + 5 + 7 + … + 199 4) 8. 4. 34. 125. 25 5) (44. 52. 60) : (11. 13. 15) 6) 129. 172 – 73. 129 + 129 7) 78. 31 + 78. 24 + 22. 72 + 78. 17 | 8) 48. 55 + 52. 167 – 52. 112 9) 3. 25. 8 + 4. 6. 37 + 2. 38. 12 10) (2100 – 42) : 21 11) (64 + 27 + 28 + 29) : 32 12) 86. 8585 – 85. 8686 13) 1 - 2 + 3 - 4 + 5 - 6 + … + 101 14*) 1 + 2 – 3 – 4 + 5 + 6 – 7 – 8 +…+ 413 + 414 |
Tính hợp lý:
a) 52 - 42 + 37 - 28 + 38 + 63 b) 130 + 35.19 - 9.70 - 30
c) (11 + 13 + 15 + ... + 19).(6.8 - 48) d) (72 - 8.9):(20 + 22 + 24 - 19 + 21 + 23)
Tính hợp lý:
a, 52 – 42 + 37 – 28 + 38 + 63
b, 130 + 35.19 – 9.70 – 30
c, (11 + 13 + 15 + … + 19).(6.8 – 48)
d, (72 – 8.9):(20+22+24 – 19 +21+23)
a) 52 – 42 + 37 – 28 + 38 + 63 = (52 – 42) + (37 + 63) + (38 – 28) = 10 + 100 + 10 = 120
b) 130 + 35.19 – 9.70 – 30
= (35.19 – 9.70) + (130 – 30) = (35.19 – 9.35.2) + 100 = 35.(19 – 18) + 100 = 35 + 100 = 135
c) (11 + 13 + 15 + … + 19).(6.8 – 48) = (11+13+15+…+19).0 = 0
d) (72 – 8.9):(20+22+24 – 19 +21+23) = 0:(20+22+24 – 19 +21+23) = 0
a) 25 - 53 : 52 + 12 : 22
b) 5 [ ( 85 - 35 : 7 ) : 8 + 90 ] - 50
c) 2. [ ( 7 - 33 : 32 ) 22 + 99 ] - 100
d) 27 : 22 + 54 : 53 . 24 - 3 . 25
e) ( 35 . 37 ) : 310 + 5 . 24 - 73 : 7
f) 32 . [ ( 52 - 3 ) : 11 ] - 24 + 2 . 103
g) ( 62007 - 62006 ) : 62006
h) ( 52001 - 52000 ) : 52000
i) ( 72005 + 72004 ) : 72004
j) ( 57 + 75 ) . ( 68 + 86 ) . ( 24 - 42 )
k) ( 57 + 79 ) . ( 54 + 56 ) . ( 33 . 3 - 92 )
l) [ ( 52 . 23) - 72 . 2 ) : 2 ] 6 - 7 . 25
a)187+(921-(921+887))
b)47.75+25.47-5 mũ 2 nhân5
c)100-(150-(-44)+(-22)
Tìm x:
a) 3 mũ x+2 + 3 mũ x+3
mik ko hiểu cách bạn ghi
a) 187+ [921-(921+887)] ??? ri hã
1+2+3+4+5+6+7+7+8+9+10+11+12+13+14+45+15+16+17+18+19+20+21-56+56+48+52+78+84+54+2545+455+1454+1256-23+56+586=
1+2+3+4+....-56+56+48.......-23+56+586=6928
So sánh:
A= 5*(11*13-22*26)/22*26-44*52 và B= 138^2-690/137^2-584
Bài 1: Tìm x nguyên, biết:
a) x + 5 = 20 - (12 -7)
b)15 - (3+ 2x) = 22
c) -11 - (19 - x) = 50
d)159 - (25 - x) = 43
e) (79 - x) - 43 = - (17 - 52)
f) (7 + x) - (21 - 13) = 32
g) - x + 20 = (-15) + 8 + 13
h) - (-x + 13 -142) + 18 = 55
Xin cảm ơn!
a) \(x+5=20-\left(12-7\right)\)
\(\Rightarrow x+5=20-5\)
\(\Rightarrow x+5=15\)
\(\Rightarrow x=15-5\)
\(\Rightarrow x=10\)
b) \(15-\left(3+2x\right)=2^2\)
\(\Rightarrow3+2x=15-4\)
\(\Rightarrow3+2x=11\)
\(\Rightarrow2x=11-3\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=\dfrac{8}{2}\)
\(\Rightarrow x=4\)
c) \(-11-\left(19-x\right)=50\)
\(\Rightarrow19-x=-11-50\)
\(\Rightarrow19-x=-61\)
\(\Rightarrow x=61+19\)
\(\Rightarrow x=80\)
d) \(159-\left(25-x\right)=43\)
\(\Rightarrow25-x=159-43\)
\(\Rightarrow25-x=116\)
\(\Rightarrow x=25-116\)
\(\Rightarrow x=-91\)
e) \(\left(79-x\right)-43=-\left(17-52\right)\)
\(\Rightarrow\left(79-x\right)-43=52-17\)
\(\Rightarrow79-x-43=35\)
\(\Rightarrow36-x=35\)
\(\Rightarrow x=1\)
f) \(\left(7+x\right)-\left(21-13\right)=32\)
\(\Rightarrow7+x-8=32\)
\(\Rightarrow x-1=32\)
\(\Rightarrow x=32+1\)
\(\Rightarrow x=33\)
g) \(-x+20=-15+8+13\)
\(\Rightarrow-x+20=6\)
\(\Rightarrow x=20-6\)
\(\Rightarrow x=14\)
h) \(-\left(-x+13-142\right)+18=55\)
\(\Rightarrow x-13+142+18=55\)
\(\Rightarrow x+147=55\)
\(\Rightarrow x=55-147\)
\(\Rightarrow x=-92\)