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a, \(\dfrac{-7}{9}.2\dfrac{3}{4}\)
= \(\dfrac{-7}{9}.\dfrac{11}{4}\)
= \(\dfrac{-77}{36}\)
b, \(\dfrac{2}{3}+\dfrac{1}{3}.\dfrac{-2}{5}\)
= \(\dfrac{2}{3}+\dfrac{-2}{15}\)
= \(\dfrac{10}{15}+\dfrac{-2}{15}\)
= \(\dfrac{-8}{15}\)
c , \(\dfrac{2}{3}-4\left(\dfrac{1}{2}+\dfrac{3}{4}\right)\)
= \(\dfrac{2}{3}-4.\dfrac{5}{4}\)
= \(\dfrac{2}{3}-5\)
= \(\dfrac{-13}{3}\)
d, \(\left(\dfrac{1}{-3}+\dfrac{5}{6}\right).11-7\)
= \(\dfrac{1}{2}\) . 11 - 7
= \(\dfrac{11}{2}-\dfrac{14}{2}\)
= \(\dfrac{-3}{2}\)
e, \(\dfrac{3}{4}.15\dfrac{1}{3}-\dfrac{3}{4}.43\dfrac{1}{3}\)
= \(\dfrac{3}{4}.\left(15\dfrac{1}{3}-43\dfrac{1}{3}\right)\)
= \(\dfrac{3}{4}.-28\)
= \(-21\)
Bài 1
a)\(\left(-\dfrac{2}{3}\right).\dfrac{3}{11}-\left(\dfrac{4}{3}\right)^2.\dfrac{3}{11}\)
\(=\dfrac{3}{11}.\left[\left(-\dfrac{2}{3}\right)-\left(\dfrac{4}{3}\right)^2\right]\)
\(=\dfrac{3}{11}.\left[\left(-\dfrac{2}{3}\right)-\dfrac{4}{3}.\dfrac{4}{3}\right]\)
\(=\dfrac{3}{11}.\left[\left(-2\right).\dfrac{4}{3}\right]\)
\(=\dfrac{3}{11}.\left(-\dfrac{8}{3}\right)\)
\(=-\dfrac{24}{33}\)
a;\(\dfrac{-6}{11}\) : \(\dfrac{12}{55}\) = \(\dfrac{-5}{2}\)
b;\(\dfrac{7}{12}\) + \(\dfrac{5}{72}\) - \(\dfrac{11}{36}\) = \(\dfrac{47}{72}\) - \(\dfrac{11}{36}\) = \(\dfrac{25}{72}\)
c;\(\dfrac{13}{10}\) : \(\dfrac{-5}{13}\) = \(\dfrac{-169}{50}\)
d; {\(\dfrac{5}{12}\) + \(\dfrac{5}{11}\) } : { \(\dfrac{5}{3}\) -\(\dfrac{7}{11}\) } = \(\dfrac{115}{132}\) : \(\dfrac{34}{33}\) = \(\dfrac{115}{136}\)
lưu ý mk ko chép đầu bài
mình cần gấp lắm đến chiều mai là phải nộp rùi
giúp mình nha thanks cá bạn trước 
ko có tâm trạng mà cười nữa
a) \(\left(4,5-2x\right)\cdot1\frac{4}{7}=\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)\cdot\frac{11}{7}=\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)=\frac{11}{7}\div\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)=1\)
\(2x=\frac{9}{2}-1\)
\(x=\frac{7}{2}\div2\)
\(x=\frac{7}{4}\)
b) \(|\frac{3}{4}\cdot x-\frac{1}{2}|-1=\frac{1}{4}\)
\(|\frac{3}{4}\cdot x-\frac{1}{2}|=\frac{1}{4}+1\)
\(|\frac{3}{4}\cdot x|=\frac{5}{4}+\frac{1}{2}\)
\(x=\frac{7}{4}\div\frac{3}{4}\)
\(x=\frac{7}{3}\)
c) \(\frac{1}{4}-|3-x|=-\frac{3}{4}\)
\(|3-x|=\frac{1}{4}-\left(-\frac{3}{4}\right)\)
\(|3-x|=1\)
\(x=3-1\)
\(\Rightarrow x=2\)
d) \(4\cdot\left(x-\frac{6}{7}\right)-\frac{3}{5}=1,4\)
\(4\cdot\left(x-\frac{6}{7}\right)-\frac{3}{5}=\frac{7}{5}\)
\(4\cdot\left(x-\frac{6}{7}\right)=\frac{7}{5}+\frac{3}{5}\)
\(4\cdot\left(x-\frac{6}{7}\right)=2\)
\(\left(x-\frac{6}{7}\right)=2\div4\)
\(x=\frac{1}{2}+\frac{6}{7}\)
\(x=\frac{19}{14}\)
\(\)
a) \(2^3=2.2.2=8\)
\(2^4=2.8=16\)
\(2^5=2.16=32\)
\(2^6=2.32=64\)
\(2^7=2.64=128\)
\(2^8=2.128=256\)
\(2^9=2.256=512\)
\(2^{10}=2.512=1024\)
b) \(4^2=4.4=16\)
\(4^3=16.4=64\)
\(4^4=64.4=256\)
Còn lại tương tự
a) \(2^{3+4+5+6+7+8+9+10}=2^{52}\)
b) \(3^{14}\)\(=4782969\)
c) \(4^9\)\(=262144\)
d) \(5^9\)\(=1953125\)
e) \(6^9\)\(=10077696\)
K mk nha, mk nhanh nha
a) A = 20 + 21 + 22 + .... + 22010
2A = 2(20 + 21 + 22 + .... + 22010)
2A = 21 + 22 + 23 + .... + 22011
A = (21 + 22 + 23 + .... + 22011) - (20 + 21 + 22 + .... + 22010)
A = 22011 - 20
A = 22011 - 1
b) B = 1 + 3 + 32 + .... + 3100
3B = 3(1 + 3 + 32 + .... + 3100)
3B = 3 + 32 + 33 + .... + 3101
2B = (3 + 32 + 33 + .... + 3101) - (1 + 3 + 32 + .... + 3100)
2B = 3101 - 1
B = (3101 - 1) : 2
c) C = 4 + 42 + 43 + .... + 4n
4C = 4(4 + 42 + 43 + .... + 4n)
4C = 42 + 43 + 44 .... + 4n + 1
3C = (42 + 43 + 44 .... + 4n + 1) - (4 + 42 + 43 + .... + 4n)
3C = 4n + 1 - 4
C = (4n + 1 - 4) : 3
d) D = 1 + 5 + 52 + .... + 52000
5D = 5(1 + 5 + 52 + .... + 52000)
5D = 5 + 52 + 53 + .... + 52001
4D = (5 + 52 + 53 + .... + 52001) - (1 + 5 + 52 + .... + 52000)
4D = 52001 - 1
4D = (52001 - 1) : 4
Bài 2:
b: x+25%x=-1,25
=>1,25x=-1,25
hay x=-1
c: x-75%x=1/4
=>1/4x=1/4
hay x=1
Bài 2:
a: =3/2-11/4=6/4-11/4=-5/4
b: =-49/6-17/2=-49/6-51/6=-100/6=-50/3
Ta có :
46 : 43 = 46-3 = 43
=> Phương án B
Vậy phương án B là phương án đúng
em chọn câu ( C) \(4^2\)