51 . 125 - 51 . 42 - 17 . 150/3+6+9+.....+99
\(51×125-51×42-17×150/3+6+9+...+99 \)
\(\frac{51.125-51.42-17.150}{3+6+9+...+99}\)=\(\frac{51.125-51.42-17.3.50}{1683}\)=\(\frac{51.125-51.42-71.50}{1683}\)=\(\frac{51\left(125-42-50\right)}{1683}=\frac{51.33}{51.33}=1\)
Tính hợp lý:
\(B=\dfrac{51\times125-51\times42-17\times150}{3+6+9...+99}\)
Tính tử: \(51.125-51.42-17.150\)
\(=51.125-51.42-17.3.50\)
\(=51.125-51.42-51.50\)
\(=51.\left(125-42-50\right)=51.33\)
Tính mẫu:
Số các số hạng: \(\left(99-3\right):3+1=33\)
Mẫu = \(33.\left(\dfrac{99+3}{2}\right)=33.51\)
\(B=1\)
Bài 1.Thực hiện các phép tính sau:a)217 320 : 4;
b) 5025:5-25:5 ;
c) 218-180:2:9 ;
d)(328-8):32
Bài 2.Thực hiện phép tính.a) 27 . 75 + 25 . 27 –150
b)12 : { 400 : [500 –(125 + 25 . 7)]}
c) 13 . 17 –256 : 16 + 14 : 7 –1
d) 18 : 3 + 182 + 3.(51 : 17)
ko có bài 3 nhé!!
Bài 4.Thực hiện phép tínha) 375 : {32 –[ 4 + (5. 32–42)]} –14
b) {210 : [16 + 3.(6 + 3. 22)]} –3
Bài 1: Thực hiện các phép tính sau:
\(a)\)Chưa rỏ đề
\(b)\)\(5025\div5-25\div5\)
\(=\)\(1005-5\)
\(=\)\(1000\)
\(c)\)\(218-180\div2\div9\)
\(=\)\(218-10\)
\(=\)\(208\)
\(d)\)\(\left(328-8\right)\div32\)
\(=\)\(320\div32\)
\(=\)\(10\)
Bài 1:
a) ( Tôi không nhìn rõ đầu bài )
b) 5025 : 5 - 25 : 5
= ( 5025 - 25 ) : 5
= 5000 : 5
= 1000
c) 218 - 180 : 2 : 9
= 218 - 180 : ( 2 . 9 )
= 218 - 180 : 18
= 218 - 10
= 208
d) ( 328 - 8 ) : 32
= 320 : 32
= 10
Bài 2: Thực hiện phép tính:
\(a)\)\(27.75+25.27-150\)
\(=\)\(27.\left(75+25\right)-150\)
\(=\)\(27.100-150\)
\(=\)\(2700-150\)
\(=\)\(2550\)
\(b)\)\(12\div\left\{400\div\left[500-\left(125+25.7\right)\right]\right\}\)
\(=\)\(12\div\left\{400\div\left[500-\left(125+175\right)\right]\right\}\)
\(=\)\(12\div\left\{400\div\left[500-300\right]\right\}\)
\(=\)\(12\div\left\{400\div200\right\}\)
\(=\)\(12\div2\)
\(=\)\(6\)
\(c)\)\(13.17-256\div16+14\div7-1\)
\(=\)\(221-16+2-1\)
\(=\)\(206\)
\(d)\)\(18\div3+182+3.\left(51\div17\right)\)
\(=\)\(6+182+3.3\)
\(=\)\(6+182+9\)
\(=\)\(197\)
a) Viết thương của mỗi phép chia sau dưới dạng phân số (theo mẫu).
Mẫu: \(5:9=\dfrac{5}{9}\) |
13 : 17 21 : 11 40 : 51 72 : 25
b) Viết (theo mẫu)
Mẫu: \(18:9=\dfrac{18}{9}=2\) |
34 : 17 20 : 5 42 : 42 0 : 6
a) Viết thương của mỗi phép chia sau dưới dạng phân số (theo mẫu).
13 : 17 = \(\dfrac{13}{17}\)
21 : 11 = \(\dfrac{22}{11}\)
40 : 51 = \(\dfrac{40}{51}\)
72 : 25 = \(\dfrac{72}{25}\)
b) Viết (theo mẫu)
34 : 17 = \(\dfrac{34}{17}\) = 2
20 : 5 =\(\dfrac{20}{5}\) = 4
42 : 42 = \(\dfrac{42}{42}\) = 1
0 : 6 = \(\dfrac{0}{6}\) = 0
Bài 2: Tính
a. 11/17 + 6/17
b. 7/15 - 4/15 - 1/15
c. 9/51 + 11/51 + 31/51
d. 9/5 - 1/5 - 3/5
a,=17/17=1
b,=7-4-1/15=2/15
c,=9+11+31/51=51/51=1
d,9-1-3/5=5/5=1
a) 11/17 + 6/17 = 1
b) 7/15 - 4/15 - 1/15 = 2/15
c) 9/51 + 11/51 + 31/51 = 1
d) 9/5 - 1/5 - 3/5 = 1
# Học tốt # k mình nha mn
\(\frac{17}{27}.\frac{-1}{_25}.\frac{_{10}5}{125}.\frac{3}{51}.\frac{9}{25}\)
2023 x 14 + 2023 x 83 +97
78 x 31 + 78 x 24 + 78 x 17 + 78 x 22 x 72
371 x 69 + 371 x 14 + 629 x 83
91 x 51 + 49 x 163 - 49 x 72
3 x 12 x 17 + 4 x 9 x 81 + 2 x 6 x 6
42 x 17 + 58 x 83 x 42 x 83 + 42 x 83 + 58 x 17
tính bằng cách hợp lý nhất
`@` `\text {Ans}`
`\downarrow`
`2023 \times 14 + 2023 \times 83+97`
`= 2023 \times (14+83) + 97`
`= 2023 \times 97 + 97`
`= 196231 +97`
`= 196328`
`78 \times 31+78 \times 24+78 \times 17+78 \times 22 \times 72`
`= 78 \times (31+24+17+22 \times 72)`
`= 78 \times (31+24+17+1584)`
`= 78 \times 1656`
`= 129168`
`371 \times 69+371 \times 14+629 \times 83`
`= 371 \times (69+14) + 629 \times 83`
`= 371 \times 83 + 629 \times 83`
`= 83 \times (371+629)`
`= 83 \times 1000`
`= 83000`
`91 \times 51+49 \times 163-49 \times 72`
`= 91 \times 51 + 49 \times (163-72)`
`= 91 \times 51+49 \times 91`
`= 91 \times (51+49)`
`= 91 \times 100`
`= 9100`
`3 \times 12 \times 17 + 4 \times 9 \times 81 + 2 \times 6 \times 6`
`= 9 \times 4 \times 17 + 4 \times 9 \times 81 + 4 \times 9 \times 2`
`= 9 \times 4 \times (17+81+2)`
`= 36 \times 100`
`= 3600`
`42 \times 17 + 58 \times 83 \times 42 \times 83 + 42 \times 83 + 17`
`= 17 \times (42+58) + 42 \times 83 \times (58 \times 83 +1)`
`= 17 \times 100 + 3486 \times 4815`
`= 1700 + 16785090`
`= 16786790`
[x cộng 32 ] - 17 .2 = 42
575- [6x cộng 70 ] =25
315 cộng [ 125 -x] = 435
[x -105] chia 21 = 15
[ 61 cộng [ 51 -x ] . 17 = 1785
575-[6x+60]=25
[6x+60]=575-25
[6x+60]=550
suy ra:
6x+60=550 hoặc 6x+60=-550
6x =550-60 6x =-550-60
6x =490 6x =-610
vậy...
[x+32]-17.2=42
[x+32]-17 =42:2
[x+32]-17 =21
[x+32] =21+17
[x+32] =28
suy ra:
x+32=28 hoặc x+32=-28
x =28-32 x =-28-32
x =-4 x =-60
315+[125-x]=435
[125-x]=435-315
[125-x]=120
suy ra:
125-x=120 hoặc 125-x=-120
x=125-120 x=125-(-120)
x=5 x=245
vậy...
Tính (-48)+127+(-52)+73 (-38)x45+(-38)x55 (-125)+371+(-875)+629+150 271+(-392)+729+(-608+(-123) (-48)x25+25x(-52) 47x(-11)+47 56-7x8+11 -42+51+2+(-11)+40
a) \(\left(-48\right)+127+\left(-52\right)+73\)
\(=\left(-48-52\right)+\left(127+73\right)\)
\(=-100+200\)
\(=100\)
b) \(\left(-38\right)\cdot45+\left(-38\right)\cdot55\)
\(=\left(-38\right)\cdot\left(45+55\right)\)
\(=\left(-38\right)\cdot100\)
\(=-3800\)
c) \(\left(-125\right)+371+\left(-875\right)+629+150\)
\(=\left(-125-875\right)+\left(371+629\right)+150\)
\(=-1000+1000+150\)
\(=150\)
d) \(271+\left(-392\right)+729+\left(-608\right)+\left(-123\right)\)
\(=\left(271+729\right)+\left(-392-608\right)-123\)
\(=1000-1000-123\)
\(=-123\)
e) \(\left(-48\right)\cdot25+25\cdot\left(-52\right)\)
\(=25\cdot\left(-48-52\right)\)
\(=25\cdot-100\)
\(=-2500\)
f) \(47\cdot\left(-11\right)+47\)
\(=47\cdot\left(-11+1\right)\)
\(=47\cdot-10\)
\(=-470\)
g) \(56-7\cdot8+11\)
\(=56-56+11\)
\(=0+11\)
\(=11\)
h) \(-42+51+2+\left(-11\right)+40\)
\(=\left(-42+2\right)+\left(51-11\right)+40\)
\(=-40+40+40\)
\(=0+40\)
\(=40\)
a: =-48-52+127+73
=200-100
=100
b; \(=-38\left(45+55\right)=-38\cdot100=-3800\)
c: \(=-125-875+371+629+150\)
=-1000+1000+150
=150
d: =271+729-392-608-123
=1000-1000-123
=-123
e: =25(-48-52)
=25*(-100)
=-2500
f: =47(-11+1)
=47(-10)
=-470
g: =56-56+11
=11
h: =-42+2+51-11+40
=-40+40+40
=40