Question

cho ab - ba = 36;a+b=12 tim ab.

 

Answer 1

ab - ba = 36

=> 10a+b- (10b+a) = 36

=> 10a+b- 10b-a = 36

=> (10a-10b)+(b-a) =36

=> 10.(a-b)+(b-a) =36

=> 10.(a-b) - (a-b) = 36

=> 9.(a-b) = 36

=> a-b = 4

=> a+b+a-b = 12+4=16

=> 2a= 16

=> a= 8

=> b = 12-8=4