a) \(23,45+x=76,986\)

\(\Rightarrow x=76,986-23,45\)

\(\Rightarrow x=53,536\)

Vậy x = 53,536

b) \(4567-x=291,378\)

\(\Rightarrow x=4567-291,378\)

\(\Rightarrow x=4275,622\)

Vậy x = 4275,622

_Chúc bạn học tốt_

a) 23,45 + X = 76,986

X = 76,986 - 23,45

X = 53,536

b) 4567 - x = 291,378

X = 4567 - 291,378

X = 4275,622

a,23,45+x=76,986

            x=76,986-23,45

           x=52,536

b,4567-x=291,45

           x=4567-291,45

           x=4275,55

A = 38,27 x 2,5 + 23,45 x 19 - 1,25 + 19 x 1,55

A = 95,675 + 445,55 - 1,25 + 29,45

A = 569,425

a)1,79 x 3 + 1,79 x 6 + 1,79

=1,79 x (3 + 6 +1)

=1,79 x 10

=17,9

b)

19,94 x 11,1 - 19,94 x 0,1 + 1000

=19,94 x (11,1 - 0,1) + 1000

=19,94 x 11 + 1000

=219,34 + 1000

=1219,34

c)

21,22 x 110,5 - 21,22 x 10 - 21,22 x 0,5

=21,22 x (110,5 - 10 - 0,5)

=21,22 x 100

=2122

d)

23,45 : 12,5 : 0,6

=23,45 : (12,5 x 0,6)

=23,45 : 7,5

=3,12

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

=(126,73^2-1+20,7)*(126-12,6*8-12,6*2)

=0

\(\left(126,74\times126,72+18,63:0,9\right)\times\left(126-12,6:0,125-12,6\times2\right)\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times\left[126-\left(12,6:0,125+12,6\times2\right)\right]\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times\left[126-\left(12,6\times8+12,6\times2\right)\right]\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times\left\{126-\left[12,6\times\left(8+2\right)\right]\right\}\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times\left[126-(12,6\times10)\right]\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times\left(126-126\right)\)

\(=\left(126,74\times126,72+18,63:0,9\right)\times0\)

\(=0\)

$\left(126,74\times 126,72+18,63:0,9\right)\times \left(126-12,6:0,125-12,6\times 2\right)$

$=\left(126,74\times 126,72+18,63:0,9\right)\times \left[126-\left(12,6:0,125+12,6\times 2\right)\right]$

$=\left(126,74\times 126,72+18,63:0,9\right)\times \left[126-\left(12,6\times 8+12,6\times 2\right)\right]$

$=\left(126,74\times 126,72+18,63:0,9\right)\times \left\{126-\left[12,6\times \left(8+2\right)\right]\right\}$

$=\left(126,74\times 126,72+18,63:0,9\right)\times \left[126-(12,6\times 10)\right]$

$=\left(126,74\times 126,72+18,63:0,9\right)\times \left(126-126\right)$

$=\left(126,74\times 126,72+18,63:0,9\right)\times 0$

$=0$

A= 38,27 x 2,5 + 23,45 x 19 - 0,54 x 1,25 + 19 x 1,55

A= 95,675 + 445,55 - 0,675 + 29,45

A= 541,225 - 0,675 + 29,45

A= 540,55 + 29,45

A= 570

A = 38,27 x 2,5 + 23,45 x 19 ‐ 1,25 + 19 x 1,55

A = 95,675 + 445,55 ‐ 1,25 + 29,45

A = 569,425 

A = 95,675 + 445,55 - 0,675 + 29,45

A = 570