\(a.\left(x\times0,25+1999\right)\times2000=2052\times2000\\ \left(x\times0,25+1999\right)\times2000=4104000\\ x\times0,25+1999=4104000:2000\\ x\times0,25+1999=2052\\ x\times0,25=2052-1999\\ x\times0,25=53\\ x=53:0,25\\ x=212\)

#)Giải :

           \(71+65.4=\frac{x+140}{x}+260\)

\(\frac{x+140}{x}+260=71+65.4\)

\(\frac{x+140}{x}+260=71+260\)

             \(\frac{x+140}{x}=71\)

         \(\frac{x}{x}+\frac{140}{x}=71\)

           \(1+\frac{140}{x}=71\)

                   \(\frac{140}{x}=71-1\)

                   \(\frac{140}{x}=70\)

                          \(x=140:70\)

                          \(x=2\)

             #~Will~be~Pens~#

\(71+65.4=\frac{x+140}{x}+260\)

\(\Rightarrow\frac{x+140}{x}+260=71+65.4\)

\(\frac{x+140}{x}+260=331\)

\(\frac{x+140}{x}=331-260=71\)

\(\frac{x}{x}+\frac{140}{x}=71\)

\(1+\frac{140}{x}=71\)

\(\frac{140}{x}=71-1=70\)

\(x=\frac{140}{70}=2\)

Vậy x=2

\(71+65\text{ x }4=\frac{x+140}{x}+260\)

\(\frac{x+140}{x}+260=71+65\text{ x }4\)

\(\frac{x+140}{x}+260=71+260\)

\(\frac{x+140}{x}=71\)

\(71x=x+140\)

\(71x-x=140\)

\(70x=140\)

\(x=140\text{ : }70\)

\(x=2\)

71 + 65 x 4 = x + 140/x + 260

x + 140/x + 260 = 71+ 65 x4

x + 140/x + 260 = 71 + 260

x + 140/x = 71

x/x + 140/x = 71

140/x = 71 - 1

140/x = 70

x = 140 : 70

x = 2

\(a,\)\(71+65\times4=\frac{x+140}{x}+260\)

\(\Rightarrow71+260=\frac{x-140}{x}+260\)

\(\Rightarrow71=\frac{x-140}{x}\)

\(\Rightarrow71x=x-140\)

\(\Rightarrow71x-x=-140\)

\(\Rightarrow70x=-140\)

\(\Rightarrow x=-2\)

\(b,\)\(y\times\frac{15}{2}-\frac{1}{3}\times\left(\frac{1}{4}+y\right)=90\frac{2}{3}\)

\(\Rightarrow\frac{15y}{2}-\frac{1}{12}-\frac{y}{3}=\frac{272}{3}\)

\(\Rightarrow\frac{90y}{12}-\frac{1}{12}-\frac{4y}{12}=\frac{1088}{12}\)

\(\Rightarrow90y-1-4y=1088\)

\(\Rightarrow86y=1089\)

\(\Rightarrow y=\frac{1089}{86}\)

hình như bn viết ngược 

                     bài giải

x + 140/x + 260=331

x nhân 2 + 140 =331-260=71

x nhân 2 =71 : 140 =0,50

      x= 0,50 : 2

      x=0,25

          hok tốt

\(71+65\) x 4 = \(\frac{x+140}{x+260}\)

=> 71 + 260 = \(\frac{x+140}{x+260}\)

=> \(331=\frac{x+140}{x+260}\)

=> \(331.\left(x+260\right)=x+140\)

=> \(331x+86060=x+140\)

=> \(331x-x=-86060+140\)

=>330x =- 85920

=> x = -2864/11

=> \(330x=-85920\)

ok nhưng tớ ko giải được like nha !

a)(x.0,25+1999)x2000=(53+1999)x2000

(x.0,25+1999)=53+1999

x.0,25=53

x=53x4

x=210

a)(x.0,25+1999)x2000=(53+1999)x2000

(x.0,25+1999)=53+1999

x.0,25=53

x=53x4

x=210

k mik đi

(x .0,25 + 1999) . 2000 = (53+1999) .2000

(x . 0,25 +1999 )= (53 +1999)

x. 0,25= 53

x         = 53 :0, 25

x         = 212

dau cham la dau nhan