G=\(\frac{3}{2.5}+\frac{3}{5.7}+\frac{3}{7.9}+...+\frac{3}{2015.2017}\)

G=\(3.\left(\frac{1}{2.5}+\frac{1}{5.7}+\frac{1}{7.9}+...+\frac{1}{2015.2017}\right)\)

G=\(3.\left(\frac{1}{2}.\frac{1}{5}+\frac{1}{5}.\frac{1}{7}+\frac{1}{7}.\frac{1}{9}+...+\frac{1}{2013}.\frac{1}{2015}+\frac{1}{2015}.\frac{1}{2017}\right)\)

G=\(3.\left(\frac{1}{2}+\frac{1}{2017}\right)\)

G=1.5

Anh ko bik có đúng ko nữa lâu quá rồi. Em thông cảm nhé

nhớ 3 câu x khác nhau nhé

ko sao a ạ

 nhung ma ko cothoi gian giai

\(S1=\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+....+\frac{2}{99.101}\)

\(S1=\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-....-\frac{1}{101}=\frac{1}{1}-\frac{1}{101}=\frac{100}{101}\)

\(S2=\frac{5}{1.3}+\frac{5}{3.5}+....+\frac{5}{99.101}\)

\(S2=\frac{5}{2}.\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-.....-\frac{1}{101}\right)=\frac{5}{2}.\left(\frac{1}{1}-\frac{1}{101}\right)=\frac{5}{2}\cdot\frac{100}{101}=\frac{250}{101}\)

làm tắt thế ai mà hỉu đc

\(B=\dfrac{2^{24}\cdot3^5-2^{24}\cdot3^4}{2^{24}\cdot3^5}+1-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{5}+...+\dfrac{1}{301}-\dfrac{1}{303}\)

\(=\dfrac{2^{24}\cdot3^4\left(3-1\right)}{2^{24}\cdot3^5}+\dfrac{302}{303}\)

\(=\dfrac{2}{3}+\dfrac{302}{303}=\dfrac{202+302}{303}=\dfrac{504}{303}\)

=168/101

a: 3^x=243

=>3^x=3^5

=>x=5

b: 4^x=4096

=>4^x=4^5

=>x=5

c: 5^3-x=25

=>3-x=2

=>x=1

d: =>2x-3=3

=>2x=6

=>x=3

j: =>2^x*8+2^x*2=80

=>2^x=8

=>x=3

a)=(-14).(-5)
=70
b)=(32-2):(-5)
=30:(-5)
=-6
c)=-72-12
=-84
d)=-35+(-4)-39
=-39-39
=-78
e)=78:(-30+36)
=78:6
=13
f)=-3.(-3)-12
=9-12
=-3
g)=45-5-2+12
=40-2+12
=38+12
=50

mình giải luôn chứ mik hông chép đề đâu nha^^

a) (-6 - 8) . (-9 + 4)

= (-14) . (-5)

= 70.

b) (8. 4 - 2) : (-5)

= (32 - 2) : (-5)

= 30 : (-5)

= -6.

c) -8. 9 - (-9 + 21)

= -8. 9 - 12

= -72 - 12

= -84.

d) -5. 7 + (-32) : 8 - (-15 + 54)

= -5. 7 + (-32) : 8 - 39

= -35 + (-32) : 8 - 39

= -35 + (-4) - 39

= -39 - 39

= -78.

e) 78 : (-6. 5 + 36)

= 78 : (-30 + 36)

= 78 : 6

= 13.

f) 15 : (-5). (-3) - 12

= -3. (-3) - 12

= 9 - 12

= -3.

g) 45 - 15 : +3 - 18 : 6 + 12

= 45 - 5 - 18 : 6 + 12

= 45 - 5 - 3 + 12

= 40 - 3 + 12

= 37 + 12

= 49.

bài 1

a)(-6-8).(-9+4)=14.(-5)=-70

b)(8.4-2):(-5)=30:(-5)=-6

c)-8.9-(-9+21)

= -8.9-12

= -72-12

= -84

d)-5.7+(-32):8-(-15+54)

= -5.7+(-32):8-39

=-35+(-4)-39

=39+(-39)

=0

e)78:(-6.5+36)

=78:6

=13

f)15:(-5).(-3)-12

=-3.(-3)-12

=9-12

=-3

g)45-15:3-18:+6+12

=45-5-3+12

=40-3+12

=37+12

=49

Đặt \(A=\frac{4}{3.5}+\frac{4}{5.7}+\frac{4}{7.9}+...+\frac{4}{99.101}\)

\(\Rightarrow\frac{1}{2}A=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{99.101}\)

\(\Rightarrow\frac{1}{2}A=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+...+\frac{1}{99}-\frac{1}{101}\)

\(\Rightarrow\frac{1}{2}A=\frac{1}{3}-\frac{1}{101}\)

\(\Rightarrow\frac{1}{2}A=\frac{101}{303}-\frac{3}{303}\)

\(\Rightarrow\frac{1}{2}A=\frac{98}{303}\)

\(\Rightarrow A=\frac{98}{303}\div\frac{1}{2}\)

\(\Rightarrow A=\frac{199}{303}\)

\(x+\frac{3}{22}=\frac{27}{121}.\frac{11}{9}\)

\(\Leftrightarrow x+\frac{3}{22}=\frac{27.11}{121.9}\)

\(\Leftrightarrow x+\frac{3}{22}=\frac{3.1}{11.1}\)

\(\Leftrightarrow x+\frac{3}{22}=\frac{3}{11}\)

\(\Leftrightarrow x=\frac{3}{11}-\frac{3}{22}\)

\(\Leftrightarrow x=\frac{6}{22}-\frac{3}{22}\)

\(\Leftrightarrow x=\frac{3}{22}\)