x+(x+1)+(x+2)+(x+3)+...+(x+100)=6060

101xX+5050=6060

101xX=1010

X=10

~~~~~~~~~~~ai đi ngang qua nhớ để lại k ~~~~~~~~~~~~~

 ~~~~~~~~~~~~ Chúc bạn sớm kiếm được nhiều điểm hỏi đáp ~~~~~~~~~~~~~~~~~~~

~~~~~~~~~~~ Và chúc các bạn trả lời câu hỏi này kiếm được nhiều k hơn ~~~~~~~~~~~~

x.101+(1+2+3+.....+100)=6060

x.101+5050=6060

x.101=6060-5050

x.101=1010

x=10

6: \(9,5\times4,7+9,5\times4,3+9,5\)

\(=9,5\times\left(4,7+4,3+1\right)\)

\(=9,5\times10=95\)

5: \(32\times1,25\times2,5+0,476+0,524\)

\(=80\times1,25+1\)

=100+1

=101

4: \(3,5\times0,5+3,5\times0,125+3,5\times22,5\times4\)

=3,5x(90+0,5+0,125)

=3,5x90,625

=317,1875

3: \(32\times1,25\times2,5+\frac{54}{10}\times8,7+5,4\times3,3-10,8\)

\(=40\times2,5+5,4\times8,7+5,4\times3,3-5,4\times2\)

=100+5,4x(8,7+3,3-2)

=100+5,4x10

=100+54

=154

2: \(15,25\times0,5+15,25\times0,25+15,25\times0,125+15,25\times6\)

=15,25x(0,5+0,25+0,125+6)

=15,25x6,875

=104,84375

1: 2020x0,56+0,34x6060+8080x0,85+2020x5,02

=2020x0,56+2020x1,02+2020x3,4+2020x5,02

=2020x(0,56+1,02+3,4+5,02)

=2020x10

=20200

= 2020 x 0,56 + 0,34 x 3 x 2020 + 2020 x 4 x 0,85 + 2020 x 5,02

= 2020 x 0,56 + 1,02 x 2020 + 2020 x 3,4 + 2020 x 5,02

= 2020 x ( 0,56 + 1,02 + 3,4 + 5,02 )

= 2020 x ( 1,58 + 3,4 + 5,02 )

= 2020 x ( 4,98 + 5,02 )

= 2020 x 10

= 20202

         ------------------Hết------------------       

Tính theo tính nhanh_________

 2020 x 0,56 + 0,36 x 6060 + 8080 x 0,85 + 2020 x 5,02 

=1131,2+2181,6+6868+10140,4 

=20321,2

   2020 x 0,56 +0,36x6060+8080x0,85+2020x5,02

=2020 x 0,56 +0,36x3x2020+4x2020x0,85+2020x5,02

=2020 x 0,56 +1,08x2020+3,4x2020+2020x5,02

=2020x(0,56+1,08+3,4+5,02)

= 2020x10,06

=20321.2

\(6060:\frac{50x+20}{x}=101\)

\(\frac{50x+20}{x}=60\)

\(50x+20=60x\)

\(10x=20\)

\(x=2\)

\(6060:\frac{50x+20}{x}=101\)

\(\frac{50x+20}{x}=6060:101\)

\(\frac{50x+20}{x}=60\)

\(50x+20=60x\)

\(10x=20\)

\(x=2\)

\(60x-50x=20\)

      A=100/1 x 2 + 100/2 x 3 + 100/3 x 4 +...+100/99 x 100

A/100=1/1 x 2 + 1/2 x 3 + 1/3 x 4 +...+1/99 x 100

A/100=2-1/1x2 + 3-2/2x3 + ... + 100-99/99x100

A/100=1-1/2 + 1/2-1/3+...+1/99-1/100

A/100=1-1/100

A/100=99/100

A=99/100x100=99

Vậy A=99.

Ta có:

\(\frac{100}{1.2}+\frac{100}{2.3}+\frac{100}{3.4}+...+\frac{100}{99.100}\)

\(\Rightarrow100.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{99.100}\right)\)

\(\Rightarrow100.\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}\right)\)

\(\Rightarrow100.\left(\frac{1}{1}-\frac{1}{100}\right)\Leftrightarrow100.\frac{99}{100}=99\)