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\(\left(13\frac{1}{4}-2\frac{5}{27}-10\frac{3}{6}\right)\)\(.230\frac{1}{25}+46\frac{3}{4}\)
\(=\)\(\left(\frac{53}{4}-\frac{59}{27}-\frac{21}{2}\right)\)\(.\frac{5751}{25}+\frac{187}{4}\)
\(=\frac{304803}{100}-\frac{12567}{25}-\frac{120771}{50}+\frac{187}{4}\)
\(=\frac{304803}{100}-\frac{50268}{100}-\frac{241542}{100}+\frac{4675}{100}\)
\(=\frac{304803-50268-241542+4675}{100}\)
\(=\frac{17668}{100}\)
\(=\frac{4417}{25}\)
B. 1/3 - 1/3 - 3/5 +3/5 + 5/7 - 5/7 + 9/11 - 9/11 -11/13 + 11/ 13 + 7/9 + 13/15
= 0 -0-0-0-0+7/9 +13/15
= 74/45
a: \(\Leftrightarrow2^x\cdot\dfrac{1}{2}+2^x\cdot2=2^{10}\left(2^2+1\right)\)
\(\Leftrightarrow2^x=2^{10}\cdot5:\dfrac{5}{2}=2^{10}\cdot5\cdot\dfrac{2}{5}=2^{11}\)
=>x=11
b: \(\Leftrightarrow3^x\cdot\dfrac{1}{3}+3^x\cdot9=3^{13}\cdot28\)
\(\Leftrightarrow3^x=3^{13}\cdot28:\dfrac{28}{3}=3^{14}\)
hay x=14
((3\(^2\)))\(^2\) - ((-5\(^2\)))\(^2\) + ((-2\(^3\)))\(^2\)
= 81 - 625 + 64
= -544+ 64
= -480
2\(^4\) + 8[(-2)\(^2\) :\(\dfrac{1}{2}\)]\(^0\) - 2\(^{-2}\). 4 + (-2)\(^2\)
= 16+ 8.1 - \(\dfrac{1}{4}\). 4 + 4
= 16+ 8- 1+4
= 27
2\(^4\) + 3(\(\dfrac{1}{2}\))\(^0\) + 2\(^{-2}\).8 + [(-2)\(^3\). \(\dfrac{1}{2^4}\)].2 - \(\dfrac{1}{2}\)
= 16 + 3.1 +\(\dfrac{1}{4}\).8 + [(-8).\(\dfrac{1}{16}\)].2 -\(\dfrac{1}{2}\)
= 16 + 3+ 2 + \(\dfrac{-1}{2}\).2- \(\dfrac{1}{2}\)
= 21 + (-1)- \(\dfrac{1}{2}\)
= 20-\(\dfrac{1}{2}\) = \(\dfrac{40}{2}\) - \(\dfrac{1}{2}\)= \(\dfrac{39}{2}\)
\(\dfrac{15^{10}.5^{10}}{75^{10}}\) + \(\dfrac{\left(0,8\right)^5}{\left(0,4\right)^6}\)
= \(\dfrac{\left(15.5\right)^{10}}{75^{10}}\) + \(\dfrac{\left(0,4.2\right)^5}{\left(0.4\right)^6}\)
= \(\dfrac{75^{10}}{75^{10}}\) + \(\dfrac{\left(0,4\right)^5.2^5}{\left(0,4\right)^6}\)
= 1 + \(\dfrac{2^5}{0,4}\) = 1+ 80 = 81
\(\dfrac{2^{13}.9^4}{6^3.8^3}\)
= \(\dfrac{2^{13}.\left(3^2\right)^4}{\left(2.3\right)^3.\left(2^3\right)^3}\) = \(\dfrac{2^{13}.3^8}{2^3.3^3.2^9}\)
= \(\dfrac{2^4.3^5}{2^3}\) = 2.3\(^5\) = 486
a)\(\frac{1}{4}-\frac{1}{3}x=\frac{2}{5}-\frac{3}{2}x\)
\(\Leftrightarrow\)\(\frac{15-20x}{60}=\frac{24-90x}{60}\)
\(\Leftrightarrow15-20x=24-90x\)
\(\Leftrightarrow-20x+90x=24-15\)
\(\Leftrightarrow70x=9\)
\(\Leftrightarrow x=\frac{9}{70}\)
c) (1/2-1/6)*3^x+4-4*3^x=3^16-4*3^13
=1/3*3^x*3^4-4*3^x=3^13*3^3-4*3^13
=27*3^x-4*3^x=3^13*(27-4)
=3^x*(27-4)=3^13*(27-4)
=>x=13
Giải:
a) \(\dfrac{1}{3}x+\dfrac{1}{5}-\dfrac{1}{2}x=1\dfrac{1}{4}\)
\(\Leftrightarrow\dfrac{1}{5}-\dfrac{1}{6}x=\dfrac{5}{4}\)
\(\Leftrightarrow\dfrac{1}{6}x=\dfrac{-21}{20}\)
\(\Leftrightarrow x=\dfrac{-63}{10}\)
Vậy ...
b) \(\dfrac{3}{2}\left(x+\dfrac{1}{2}\right)-\dfrac{1}{8}x=\dfrac{1}{4}\)
\(\Leftrightarrow\dfrac{3}{2}x+\dfrac{3}{4}-\dfrac{1}{8}x=\dfrac{1}{4}\)
\(\Leftrightarrow\dfrac{11}{8}x=\dfrac{-1}{2}\)
\(\Leftrightarrow x=\dfrac{-4}{11}\)
Vậy ...
Các câu sau làm tương tự câu b)
Bài 1 :
a) \(-3+\left(-4\right)-\left(-3\right)+\left(2+7-10\right)=-3-4+3+2+7-10=-5\)
b) \(3-\left(-3+2-7\right)+\left(-4\right)=3+3-2+7-4=7\)
c) \(7+\left(-2-3+7\right)-\left(-2\right)=7-2-3+7+2=17\)
d) \(-\left(-3\right)-\left(-2+3-8\right)+\left(-6\right)=3+2-3+8-6=4\)
Bài 2 :
a) \(x^2-2x-\left(3x-2x\right)=x^2-2x-3x+2x=x^2-3x\)
b) \(-\left(x^2+3x^2\right)-\left(-5x^2+3x\right)=-x^2-3x^2+5x^2-3x=x^2-3x\)
c) \(\left(x-y\right)-\left(x+3y+1\right)=x-y-x-3y-1=-4y-1\)
Bài 1:
a, -3+ (-4) - (-3) + (2 + 7 - 10)
= -3 - 4 + 3 + 2 + 7 - 10
= 5 - 10
= -5.
b, 3 - (-3 + 2 - 7) + (-4)
= 3 + 3 - 2 + 7 - 4
= 11 - 4
= 7
c, 7 + (-2 - 3 + 7) - (-2)
= 7 - 2 - 3 + 7 + 2
= 9 + 2
= 11.
d, - (-3) - (-2 + 3 - 8) + (-6)
= 3 + 2 - 3 + 8 - 6
= 10 - 6
= 4.
Mình chỉ làm bài 1 thôi nhé.
Chúc bạn học tốt!
1: \(\Leftrightarrow3x+4=2\)
=>3x=-2
=>x=-2/3
2: \(\Leftrightarrow7x-7=6x-30\)
=>x=-23
3: =>\(5x-5=3x+9\)
=>2x=14
=>x=7
4: =>9x+15=14x+7
=>-5x=-8
=>x=8/5