Question

 Tìm x 

a) 15 -  (25 - x) = 2x -17

b) 42 - (12 - x) = 2x -15

Các bạn giải đi, mk sẽ k cho

Answer 1

a)15-(25-x) = 2x-17

=>15-25+x = 2x-17

=>-10+x = 2x-17

=>-10+17 = 2x-x

=> x=7

Answer 2

a) 15 - (25 - x) = 2x - 17

15 - 25 + x = 2x - 17

x - 2x = -17 - 15 + 25

-x = -7

x = 7

b) 42 - (12 - x) = 2x - 15

42 - 12 + x = 2x - 15

x - 2 = -15 - 42 + 12

-x = -45

x = 45

Answer 3

b) 42-(12-x) = 2x-15

=> 42-12+x = 2x-15

=>30+x = 2x-15

=>30+15 = 2x-x

=> x=45

Answer 4

a) 15 - ( 25 -x ) = 2x - 17

=> 15 - 25 + x = 2x - 17 

=> x-2x = -17 - 15 + 25

=> -x =-7

=> x = 7

 Vậy x = 7

b) 42 - ( 12 -x ) = 2x - 15

=> 42 - 12 + x = 2x -15

=>x - 2x = -15 - 42 + 12

=> -x = -45

=> x = 45

Vậy x = 45