Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) (x - 34) . 15 = 0
x - 34 = 0
x = 34
b) 18 . (x - 16) = 18
x - 16 = 18 : 18
x - 16 = 1
x = 1 + 16
x = 17
(x – 16) = 18 : 18 (x – 16) = 0 x = 16 Hok tốt |
\(\left(2+x\right)+\left(4+x\right)+\left(6+x\right)+...+\left(52+x\right)=780\)
\(\Leftrightarrow26x+\left(2+4+6+...+52\right)=780\)
\(\Leftrightarrow26x+\left[\left(52+2\right).26:2\right]=780\)
\(\Leftrightarrow26x+702=780\)
\(\Leftrightarrow26x=78\)
\(\Leftrightarrow x=\frac{78}{26}=3\)
c1 : Ư(6) = {1;2;3;6}
Ư(12) = {1;2;3;4;6;12}
Ư(42) = {1;2;3;6;7;14;21;42}
ƯC(6;12;42) ={1;2;3;6}
c2 : phân tích các số thành thừa số nguyên tố
6 = 2 x 3
15 = 3 x 5
42 = 2 x 3 x 7
---> ưcln ( 6,15,42 ) = 2 x 3 = 6
ưc ( 6 , 15 , 42 ) = ư ( 6 ) = { 1 ; 2 ; 3 ; 6 }
\(\frac{-3}{4}.\frac{2}{11}+\frac{3}{4}.\frac{9}{11}+2\frac{3}{4}\)
\(=\frac{3}{4}.\frac{-2}{11}+\frac{3}{4}.\frac{9}{11}+2+\frac{3}{4}\)
\(=\frac{3}{4}.\left(\frac{-2}{11}+\frac{9}{11}+1\right)+2\)
\(=\frac{3}{4}.\frac{18}{11}+2\)
\(=\frac{3.2.9}{2.2.11}+2\)
\(=\frac{3.9}{2.11}+2\)
\(=\frac{27}{22}+\frac{2}{1}\)
\(=\frac{27}{22}+\frac{44}{22}\)
\(=\frac{71}{22}\)
\(=3\frac{5}{22}\)
Chúc bạn học tốt!!!
| + | \(-\frac{1}{2}\) | \(\frac{5}{9}\) | \(\frac{1}{36}\) | \(-\frac{11}{18}\) |
| \(-\frac{1}{2}\) | -1 | \(\frac{1}{18}\) | -\(\frac{17}{36}\) | -\(\frac{10}{9}\) |
| \(\frac{5}{9}\) | \(\frac{1}{18}\) | 1 | \(\frac{7}{12}\) | \(-\frac{1}{18}\) |
| \(\frac{1}{36}\) | \(\frac{17}{36}\) | \(\frac{7}{12}\) | 1 | \(-\frac{7}{12}\) |
| \(-\frac{11}{18}\) | \(-\frac{10}{9}\) | \(-\frac{1}{18}\) | \(\frac{7}{12}\) | -1 |
a: \(5\cdot11\cdot18+9\cdot31\cdot10+4\cdot29\cdot45\)
\(=11\cdot\left(5\cdot18\right)+31\cdot\left(9\cdot10\right)+29\cdot2\cdot\left(2\cdot45\right)\)
\(=90\left(11+31+29\cdot2\right)\)
\(=90\cdot100=9000\)
b: \(37\cdot39+78\cdot14+13\cdot85+52\cdot55\)
\(=37\cdot39+39\cdot2\cdot14+13\cdot85+13\cdot4\cdot55\)
\(=39\left(37+2\cdot14\right)+13\cdot\left(85+4\cdot55\right)\)
\(=39\cdot65+13\cdot305\)
\(=13\left(65\cdot3+305\right)=13\cdot500=6500\)
a)
5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45
=90.11+90.31+2.29.90=90.11+90.31+2.29.90
=90.(11+31+2.29)=90.(11+31+2.29)
=90.100=9000
b)
37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55
=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11
=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44
=39.65+65.(17+44)=39.65+65.(17+44)
=39.65+65.61=39.65+65.61
=65.(39+61)=65.(39+61)
=65.100=6500