X+ 0,1+X+0,2+...+X+0,5=5,55

<=> 5x X + (0,5+0,1) x 5 :2 = 5,55

<=> 5 x X + 1,5 = 5,55

<=> 5 x X= 5,55- 1,5

<=> 5 x X= 4,05

<=>X= 4,05:5

<=>X=0,81

mik cần gấp ạ

Ta có: x+0,1+x+0,2+x+...+x+0,5=5,55

nên 5x+1,5=5,55

\(\Leftrightarrow5x=4,05\)

hay x=0,81

Vậy: x=0,81

chúc học tốt nhé

x = 13,6

( 11 x 9 - 900 x 0.1- 8) x ( 56.7 x 0.5 + 56.7 x 9.5)

=(99 - 90 - 8) x [56.7(0.5+9.5)]

=1 x [56.7x10]

=1x 567=567

( 11 x 9 - 900 x 0.1- 8) x ( 56.7 x 0.5 + 56.7 x 9.5)

=(99 - 90 - 8) x [56.7(0.5+9.5)]

=1 x [56.7x10]

=1x 567=567

\(a.7,15:0,5+7,15.9-7,15=7,15.\left(2+1-1\right)\)

                                                           \(=7,15.10=71,5.\)

\(b.3,14:0,1+75\%.3,14+3,14:0,125+81,25.3,14=3,14.\left(10+\frac{3}{4}+8+81,25\right)\)

                                                                                                           \(=3,14.100=314.\)

7.15*2+7.15*9-7.15

7.15*(2+9-1)

7.15*10

71.5 

b, 3.14*10+7.5*3.14+3.14*8+81.25*3.14

=314*(10+7.5+8+81.25)

=3.14*106.75

=355.195

\(\frac{x}{10}\)^2019+(0,1)^2019=\(\frac{1}{10}\)^2019 \(\frac{x}{10}\)^2019 =(0,1)^2019-(0,1)^2019 \(\frac{x}{10}\)^2019 =0 \(\frac{x}{10}\)^2019 =0^2019 \(\frac{x}{10}\) =0 x =0

\(a.=\dfrac{2019}{2020}\times\left(\dfrac{4}{11}+\dfrac{5}{11}+\dfrac{2}{11}\right)\\ =\dfrac{2019}{2020}\times1=\dfrac{2019}{2020}\\ b.=\dfrac{25}{27}\times\left(\dfrac{17}{14}-\dfrac{1}{14}-\dfrac{2}{14}\right)\\ =\dfrac{25}{27}\times1=\dfrac{25}{27}\)

Thanks mik chữ cũng hơi ẩu

hì...mơn anh

thiếu 1 số chỗ đó

 cứ thấy sai sai chỗ nào ý

2019 x 74+ 2019 x 25 + 2019

2019 x 74 + 2019 x 25 + 2019 x 1

2019 x (74 + 25 + 1)

2019 x 100

= 201900

2019 x 74+ 2019 x 25 + 2019=201900