https://bom.so/zZ21LQ 

Tham khảo ở  đây nè

a: \(102,7-x:1,5=87,62\)

=>x:1,5=102,7-87,62=15,08

=>\(x=15,08\times1,5=22,62\)

b: \(38,23+x:2,5=42,76\)

=>x:2,5=42,76-38,23=4,53

=>\(x=4,53\times2,5=11,325\)

$\mathrm{a)102},7-x:1,5=87,62$

$x:1,5=102,7-87,62$

$x:1,5=15,08$

$x=15,08\times 1,5$

$x=22,62$

Vậy $x=22,62$

$b)38,23+x:2,5=42,76$

$x:2,5=42,76-38,23$

$x:2,5=4,53$

$x=4,53\times 2,5$

$x=11,325$

Vậy $x=11,325$

1994 chia 4 dư 3

=>\(93^{1999}\) sẽ có chữ số tận cùng là 7

1997 chia 4 dư 1

=>\(57^{1997}\) sẽ có chữ số tận cùng là 7

=>\(C=93^{1999}-57^{1997}\) sẽ có chữ số tận cùng là 0

=>C chia hết cho 5

1 We did not go to school last week.

2 What does he want to do?

3 She goes swimming once a week.

4 I always eat breakfast at six.

5 What is the weather like in autumn?

6 He and his sister are listening to music in the room at the moment.

7 Where will you go for your holiday next summer?

1) We didn't go to school last week .

2) What does he want do ?

3)She goes swim once a week .

4)I always eat beakfast at six o'clock . 

5) What  is the weather like in autumn ?

6) He and her sister listen music in room at the moment 

7) Where will you go for your holiday next summer? 

a) 125,75 - 12,5 x X = 100,25

                  12,5 x X = 125,75 - 100,25

                  12,5 x X = 25,5

                             X = 25,5 : 12,5

                             X = 2,04

Vậy X = 2,04

b) 27,5 - 20,7 : X = 10,25

               20,7 : X = 27,5 - 10,25

               20,7 : X = 17,25

                         X = 20,7 : 17,25

                         X = 1,2

Vậy X = 1,2

$\mathrm{a)125},75-12,5\times x=100,25$

$12,5\times x=125,75-100,25$

$12,5\times x=25,5$

$x=25,5:12,5$

$x=2,04$

Vậy $x=2,04$

$\mathrm{b)27},5-20,7:x=10,25$

$20,7:x=27,5-10,25$

$20,7:x=17,25$

$x=20,7:17,25$

$x=1,2$

Vậy $x=1,2$

\(3,75+x\times0,5=18,25\)

=>\(x\times0,5=18,25-3,75=14,5\)

=>x=14,5:0,5=29

Khối lượng của 1 bao gạo là:

\(25:\dfrac{1}{4}=100\left(kg\right)\)

Khối lượng của 10 bao gạo là:

10x100=1000(kg)=10(tạ)

\(29,5-x\times0,25=20,5\)

\(x\times0,25=29,5-20,5\)

\(x\times0,25=9\)

\(x=9:0,25\)

\(x=36\)

\(29,5-x\times0,25=20,5\)

=>\(x\times0,25=29,5-20,5=9\)

=>x=9:0,25=36

-765-(305+x)=100

=>x+305=-765-100=-865

=>x=-865-305=-1170