Question

Tìm x :

10 + 10 = 30 - x

20 - 10 = 100 - x

Answer 1

10 + 10 = 30 - x

20 = 30 - x

x = 30 - 20

x = 10

20 - 10 = 100 - x 

10 = 100 - x

x = 100 - 10

x = 90

Answer 2

Tìm x :

10 + 10 = 30 - x

20 - 10 = 100 - x

10 + 10 = 30 - x

20 = 30 - x

30 - x = 20

x = 30 - 20 = 10

20 - 10 = 100 - x

10= 100 - x 

100 - x = 10

x = 100 - 10 = 90

Answer 3

10+10=30-x

=>30-x=10+10

=>30-x=20

=>x=30-20

=>x=10

20-10=100-x

=>100-x=20-10

=>100-x=10

=>x=100-10

=>x=90

Answer 4

10+10=30-x

=>30-x=10+10

=>30-x=20

=>x=30-20

=>x=10

20-10=100-x

=>100-x=20-10

=>100-x=10

=>x=100-10

=>x=90

Answer 5

10+10=30-x

=>30-x=10+10

=>30-x=20

=>x=30-20

=>x=10

20-10=100-x

=>100-x=20-10

=>100-x=10

=>x=100-10

=>x=90

Answer 6

10 + 10 = 30 - x

20 = 30 - x

x = 10

20 - 10 = 100 - x

10 = 100 - x

x = 90

Answer 7

10+10= 30-x

20=30-x

30-x=20

x= 30-20

x= 10

20-10= 100-x

10= 100-x

100-x= 10

x= 100-10

x= 90

tk nhé mình cần điểm hỏi đáp

Answer 8

a, 10 + 10 = 30 - x

           20 = 30 - x

           20 = 30 - 10

    => x=10

b, 20 - 10 = 100 - x

          10 = 100 - x

          10 = 100 - 90

   => x=90