4,5 : 0,3 =2.25 : (0,1 . x)

15=50:(0,1.x)

=>0,1.x=50:15

0,1.x=10/3

x=10/3:0,1

x=100/3

a. ( 48 x 0,75 - 240 : 10 ) - ( 16 x 0,5 - 16 : 4 )

=(36-24)-(8-4)

=12-4

=8

b. (1000 x 0,1 - 900 x 0,1 - 90 x 0,1 ) x ( 142 x 0,5 - 240 x 0,25 )

=(100-90)x(71-60)

=10x11

=110

# mui #

a 

= ( 24 + 12 ) - ( 9 - 4 ) 

= 36 - 5 

= 31 

đáp số : 50

100,05

=100,05

100,05

a) \(210:x=2,1:0,25=8,4\)

\(x=210:8,4=25\)

b) \(x.2+x.0,5=6,25\)

\(2,5x=6,25\)

\(x=6,25:2,5=2,5\)

c) \(x:0,25-x=15,6\)

\(3x=15,6\)

\(x=5,2\)

d) \(x:12,5=3,75.4=15\)

\(x=15.12,5=187,5\)

e) \(x.12,6-x.5,6=42\)

\(7x=42\)

\(x=6\)

g) \(x:0,1-x:4-x.0,75=2,25\)

\(10x-\dfrac{x}{4}-\dfrac{3x}{4}=2,25\)

\(9x=2,25\)

\(x=0,25\)

giúp mình gấp mn

wth khó thế

A = ( 2022 x 0,75 + 2022 : 4) - ( 2021 : 0,1 : 10)

= (2022 x 0,75 + 2022 x 0,25) - ( 2021 : 1/10 : 10)

= 2022 x(0,75+0,25) - 2021x 10 : 10

= 2022x 1 - 2021

= 2022 - 2021

=1

a, x . 9,9 + x : 10 = 12,5

\(x.\frac{99}{10}+x.\frac{1}{10}=\frac{25}{2}\)

\(x\left(\frac{99}{10}+\frac{1}{10}\right)=\frac{25}{2}\)

\(x.10=\frac{25}{2}\)

\(x=\frac{25}{2}:10=\frac{25}{2}.\frac{1}{10}=\frac{5}{4}\)

b, \(x:\frac{1}{4}-x=\frac{78}{5}\)

\(x.4-x=\frac{78}{5}\)

\(x\left(4-1\right)=\frac{78}{5}\)

\(x.3=\frac{78}{5}\)

\(x=\frac{78}{5}:3=\frac{78}{5}.\frac{1}{3}=\frac{26}{5}\)

c, \(x:\frac{1}{10}-x:4-x.\frac{3}{4}=\frac{9}{4}\)

\(=x.10-x.\frac{1}{4}-x.\frac{3}{4}=\frac{9}{4}\)

\(x\left(10-\frac{1}{4}-\frac{3}{4}\right)=\frac{9}{4}\)

\(x.9=\frac{9}{4}\)

\(x=\frac{9}{4}:9=\frac{9}{4}.\frac{1}{9}=\frac{1}{4}\)

**** 

a, x . 9,9 + x : 1 0 = 1 2,5 x. 1 0 9 9 + x. 1 01 = 225 x 1 0 9 9 + 1 01 = 225 x.1 0 = 225 x = 225 :1 0 = 225 . 1 01 = 45 b, x: 41 − x = 578 x.4 − x = 578 x 4 − 1 = 578 x.3 = 578 x = 578 :3 = 578 . 31 = 526 c, x: 1 01 − x:4 − x. 43 = 49 = x.1 0 − x. 41 − x. 43 = 49 x 1 0 − 41 − 43 = 49 x.9 = 49 x = 49 :9 = 49 . 91 = 4

Lời giải:

$=(792,36\times 0,75+792,36\times 0,25):(7,2\times 10:10)$

$=792,36\times (0,75+0,25):7,2$

$=792,36\times 1:7,2=792,36:7,2=110,05$

729,81

729,81

729,81