a) (x + 5) / 95 + (x +10)/90 + (x + 15)/85 + (x + 20)/80 = -4

<=> (x + 5)/95 + (x + 5)/90 + 5/90 + (x + 5)/85 + 10/85+ (x + 5)/80 + 15/80 = -4

<=> (x + 5)(1/95+1/90+1/85+1/80) =-4 -5/90-10/85-15/85

<=> (x + 5)(1/95+1/90+1/85+1/80)= -1-(1 + 5/90 )-(1 + 10/85)  - (1 + 15/80)

<=>(x + 5)(1/95+1/90+1/85+1/80) = -1 - 95/90 - 95/85 - 95/80

<=>(x + 5)(1/95+1/90+1/85+1/80) = -95 (1/95+1/90+1/85+1/80)

<=> x + 5 = -95 => x = -100

b) Làm tương tự phần a => Kết quả x = 100

giúp mình với

Ta có :

\(\frac{x-3}{97}+\frac{x-27}{73}+\frac{x-67}{33}+\frac{x-73}{27}=4\)

\(\Leftrightarrow\left(\frac{x-3}{97}-1\right)+\left(\frac{x-27}{73}-1\right)+\left(\frac{x-67}{33}-1\right)+\left(\frac{x-73}{27}-1\right)=0\)

\(\Leftrightarrow\frac{x-100}{97}+\frac{x-100}{73}+\frac{x-100}{33}+\frac{x-100}{27}=0\)

\(\Leftrightarrow\left(x-100\right)\left(\frac{1}{97}+\frac{1}{73}+\frac{1}{33}+\frac{1}{27}\right)=0\)

Vì \(\frac{1}{97}+\frac{1}{73}+\frac{1}{33}+\frac{1}{27}>0\) Nên \(x-100=0\)

\(\Leftrightarrow x=100\)

Vậy \(x=100\)

\(\Leftrightarrow\frac{x-3}{87}+\frac{x-27}{79}+\frac{x-67}{33}+\frac{x-73}{27}-4=0\)

\(\Leftrightarrow\left(\frac{x-3}{97}-1\right)+\left(\frac{x-27}{73}-1\right)+\left(\frac{x-67}{33}-1\right)+\left(\frac{x-73}{27}-1\right)=0\)

\(\Leftrightarrow\left(\frac{x-3-97}{97}\right)+\left(\frac{x-27-73}{73}\right)+\left(\frac{x-67-33}{33}\right)+\left(\frac{x-73-27}{27}\right)=0\)

\(\Leftrightarrow\frac{x-100}{97}+\frac{x-100}{73}+\frac{x-100}{33}+\frac{x-100}{27}=0\)

\(\Leftrightarrow\left(x-100\right)\left(\frac{1}{97}+\frac{1}{73}+\frac{1}{33}+\frac{1}{27}\right)=0\)

Vì \(\frac{1}{97}+\frac{1}{73}+\frac{1}{33}+\frac{1}{27}\ne0\)

\(\Rightarrow x-100=0\Leftrightarrow x=100\)

\(\frac{x-3}{97}+\frac{x-27}{73}+\frac{x-67}{33}+\frac{x-73}{27}=4\)    

\(\frac{x-3}{97}-1+\frac{x-27}{73}-1+\frac{x-67}{33}-1+\frac{x-73}{27}-1=4-1-1-1-1\)     

\(\frac{x-100}{97}+\frac{x-100}{73}+\frac{x-100}{33}+\frac{x-100}{27}=0\)    

\(\left(x-100\right)\left(\frac{1}{97}+\frac{1}{73}+\frac{1}{33}+\frac{1}{27}\right)=0\)   

\(x-100=0\) 

\(x=100\)

\(\dfrac{x-13}{87}+\dfrac{x-27}{73}+\dfrac{x-67}{83}+\dfrac{x-73}{27}=4\)

<=>\(\dfrac{x-13}{87}-1+\dfrac{x-27}{73}-1+\dfrac{x-67}{83}-1+\dfrac{x-73}{27}-1=0\)

<=>\(\dfrac{x-100}{87}+\dfrac{x-100}{73}+\dfrac{x-100}{83}+\dfrac{x-100}{27}=0\)

<=>\(\left(x-100\right)\left(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}\right)=0\)

Do \(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}>0\)

=>x-100=0

<=>x=100

\(\dfrac{x-13}{87}+\dfrac{x-27}{73}+\dfrac{x-67}{83}+\dfrac{x-73}{27}=4\)

\(\Rightarrow\left(\dfrac{x-13}{87}-1\right)+\left(\dfrac{x-27}{73}-1\right)+\left(\dfrac{x-67}{83}-1\right)+\left(\dfrac{x-73}{27}\right)=0\)

\(\Rightarrow\dfrac{x-100}{87}+\dfrac{x-100}{73}+\dfrac{x-100}{83}+\dfrac{x-100}{27}=0\)

\(\Rightarrow\left(x-100\right)\left(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}\right)=0\)

\(\Rightarrow x-100=0\Rightarrow x=100\)

\(\frac{x+73}{27}+1+\frac{x+74}{26}+1=\frac{x+27}{73}+1+\frac{x+26}{74}+1\)

\(\frac{x+73+27}{27}+\frac{x+74+26}{26}=\frac{x+27+73}{73}+\frac{x+26+74}{74}\)

\(\frac{x+100}{27}+\frac{x+100}{26}=\frac{x+100}{73}+\frac{x+100}{74}\)

\(\left(x+100\right)\left(\frac{1}{27}+\frac{1}{26}-\frac{1}{73}-\frac{1}{74}\right)=0\)

mà \(\frac{1}{27}+\frac{1}{26}-\frac{1}{73}-\frac{1}{74}\ne0\)

\(\Rightarrow x+100=0\Rightarrow x=-100\)

x - 13/87 + x - 27/73 + x- 67/33 + x - 73/27 = 4

x * 4 + ( 13/87 - 27/73 - 7/33 - 73/27 ) = 4

x * 4 + ( cậu tự tính được ko ? ) = 4

x * 4 +  kết quả trên = 4 

Đến đây cậu tính được rồi chứ ! Hì hì ........... Tớ kinh tính toán quá ! Sory Đức Anh nha !

\(\frac{x-85}{15}+\frac{x-74}{13}+\frac{x-67}{11}+\frac{x-64}{9}=10\\ \Leftrightarrow\left(\frac{x-85}{15}-1\right)+\left(\frac{x-74}{13}-2\right)+\left(\frac{x-67}{11}-3\right)+\left(\frac{x-64}{9}-4\right)=10-10\\ \Leftrightarrow\frac{x-100}{15}+\frac{x-100}{13}+\frac{x-100}{11}+\frac{x-100}{9}=0\\ \Leftrightarrow\left(x-100\right)\left(\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\right)\Leftrightarrow x-100=0\left(Vi\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\ne0\right)\Leftrightarrow x=100\)

Tìm x :

x - 0,27 = \(\frac{73}{100}\)

x           = \(\frac{73}{100}+0,27\)

x           = 1

Cậu P khó quá mik chưa nghĩ ra cách tính nhanh nhất !

Cậu tự giải nhé !

Hok tốt

\(x-0,27=\frac{\frac{73}{77}+\frac{73}{165}+\frac{73}{285}}{25\times\left(\frac{5}{84}+\frac{3}{180}+\frac{4}{285}\right)}.\)

\(x-0,27=\frac{\frac{146}{105}+\frac{73}{285}}{25\times\left(\frac{8}{105}+\frac{4}{285}\right)}\)

\(x-0,27=\frac{\frac{219}{133}}{25\times\frac{12}{133}}\)

\(x-0,27=\frac{\frac{219}{133}}{\frac{300}{133}}\)

\(x-0,27=0,73\)

\(x=0,73+0,27\)

\(x=1\)

\(\frac{\left(\frac{518}{19}-\frac{342}{13}\right).\left(\frac{177}{236}+\frac{76}{236}-\frac{6}{236}\right)}{\left(\frac{3}{4}+x\right).\frac{27}{33}}=1\)

=>\(\frac{\left(\frac{6734}{247}-\frac{6498}{247}\right).\frac{247}{236}}{\left(\frac{3}{4}+x\right).\frac{27}{33}}=1\)

=>(3/4+x)*27/33=236/247*247/236=1

3/4+x=1:27/33=33/27

x=33/27-3/4=132/108-81/108

x=51/108

Vậy x=51/108

tính tử rồi nhân chéo lên tìm x

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