\( {5 +6 \over 2-1}+{6+7 \over 5+6}\)
Bài 1:So sánh
A=10/22017+10/22018 và B=11/22017+92018
Bài 2
\(A = {1 \over 2}.{3\over 4}.{4\over 5}.{5\over 6}.{7\over 8}. ... .{99\over 100}\) và \(x = {2\over 3}.{4\over 5}.{6\over 7}.{8\over 9}. ... .{100\over 101}\)
a,So sánh
b,Chứng minh A<1/16
1.
\(A = {3 \over 5}.{2017 \over 2016} - {3 \over 5}- {1 \over 2016} + {2 \over 5}\)
\(B = ({12 \over 199}+ {23 \over 200} - {34 \over 201}).({1\over 2} - {1 \over 3}-{1 \over 6})\)
\(C= 2{1 \over 3}+{11 \over 5}: 33-{1 \over 50}.\)(-5)2
\(D = {4^5 . 9^4 - 10 . 6^9 \over 2^10 . 3^8 + 6^8 . 28}\)
E =( -1).(-1)2.(-1)3.(-1)4......(-1)2014
2.
\(A= {5\over2.4} + {5\over4.6} + {5\over6.8} + .....+ {5\over48.50}\)
\(B={1\over3.6} + {1\over6.9} + {1\over9.12} +.....+{1\over30.33}\)
So sánh các số hữu tỉ:
a) \( {-23 \over 27}; {-24 \over 25}\)
b) \( {-5 \over 6}; {6 \over -7} ; {-7 \over 8}\)
\(-23\frac{2}{7};-24\frac{2}{5}\)
Ta có : -23 > -24 \(\Leftrightarrow\)\(-23\frac{2}{7}>-24\frac{2}{5}\)
a) \({{7} \over 5}\) + \( {{4} \over 7}\)- \( {{9} \over 10}\)=
b) 2 + \({{3} \over 4}\) x \({{8} \over 5}\)=
c)\({{9} \over 8}\) - \({{6} \over 5}\): \({{8} \over 5}\)=
d) 6 : \({{9} \over 7}\) x \({{3} \over 10}\)=
(Làm rõ ràng và đề bài cho là "Tính")
Giải các phương trình sau :
a, \({8 \over x-8} + { 11\over x-11} = {9 \over x-9} +{10 \over x-10}\)
b, \({x \over x-3} - {x \over x-5} = { x \over x-4} - { x\over x-6}\)
c, \({ 4\over x^2 - 3x + 2 } - { 3 \over 2x^2 - 6x +1 } +1 =0\)
d, \({1\over x-1} + {2\over x-2} + {3 \over x-3} = {6 \over x-6}\)
e, \({2\over 2x+1} - {3 \over 2x-1} = {4\over 4x^2 -1}\)
f, \({ 2x\over x +1 } + { 18 \over x^2 +2x-3} = {2x-5 \over x+3}\)
g, \({1 \over x-1} + { 2x^2 -5 \over x^3 -1 } = { 4 \over x^2 +x+1}\)
a, 8/x-8 + 11/x-11 = 9/x-9 + 10/ x-10
b, x/x-3 - x/x-5 = x/x-4 - x/x-6
c, 4/x^2-3x+2 - 3/2x^2-6x+1 +1 = 0
d, 1/x-1 + 2/ x-2 + 3/x-3 = 6/x-6
e, 2/2x+1 - 3/2x-1 = 4/4x^2-1
f, 2x/x+1 + 18/x^2+2x-3 = 2x-5 /x+3
g, 1/x-1 + 2x^2 -5/x^3 -1 = 4/ x^2 +x+1
rút gọn biểu thức:
\({ 3-\ 2\sqrt{2} \over 1-√2}\)\({5 \ \sqrt{6} -15 \over 6-2√6}\)\({x \ \sqrt{x}-y√y \over x-y}\)(√5+√3+√2)*(√5+√2-√3)\(\left(\sqrt{5}+\sqrt{3}+\sqrt{2}\right).\left(\sqrt{5}+\sqrt{2}-\sqrt{3}\right)\)
\(=\left(\sqrt{5}+\sqrt{2}\right)^2-\left(\sqrt{3}\right)^2\)
\(=7+2\sqrt{10}-3\)
\(=4+2\sqrt{10}\)
GIẢI PHƯƠNG TRÌNH BẬC NHẤT MỘT ẨN
1. 3(x+2) = 5x+8
2. 2(x-1) = 3(3+x)+3
3. 5-(x-6) = 4(3-2x)
4. \({2x + 3\over 3} + {2x-1\over 6} = 4- {x \over 3}\)
6. \({10x + 3\over 12} =1 + {6 + 8x\over 9}\)
1) 3(x + 2) = 5x + 8
<=> 3x + 6 = 5x + 8
<=> 3x + 6 - 5x - 8 = 0
<=> -2x - 2 = 0
<=> -2x = 0 + 2
<=> -2x = 2
<=> x = -1
2) 2(x - 1) = 3(3 + x) + 3
<=> 2x - 2 = 9 + x + 3
<=> 2x - 2 = 12 + x
<=> 2x - 2 - 12 - x = 0
<=> x - 14 = 0
<=> x = 0 + 14
<=> x = 14
3) 5 - (x - 6) = 4(3 - 2x)
<=> 5 - x + 6 = 12 - 8x
<=> 11 - x = 12 - 8x
<=> 11 - x - 12 + 8x = 0
<=> -1 + 7x = 0
<=> 7x = 0 + 1
<=> 7x = 1
<=> x = 1/7
a. 2016 : [ 25 - (3x + 2)] = 32 . 7
b, 52x - 3 - 2 . 52 = 52 . 3
c,\({-3 \over 4x}-{20 \over 11.13}-{20 \over 13.15}-{20 \over 15.17}-.....-{20 \over 53.55}={3 \over 11}\)
d,\({x \over 6}+{x \over 10}+{x \over 15}+{x \over 21}+{x \over 28}+{x \over 36}+{x \over 45}+{x \over 55}+{x \over 66}+{x \over 78}={220 \over 39}\)
e, x+(x-1)+(x-2)+(x-3)+......+(x-2016) = 2033136
3-7\(7\over \ 12\)<x<-\(5\over \ 9\) : (\(5 \over \ 9\) - \(1 \over \ 6\)) mà x\(\in\) Z
Tìm x