Question

Aflati multimea perechilor (x,y) care verifica egalitatea 0.x(y)-0,y(x)=o,o(8)​

Answer 1

Răspuns:

Explicație pas cu pas:

$\dfrac{xy-x}{90} -\dfrac{yx-y}{90} =\dfrac{8}{90},~|*9 ,~xy-x-(yx-y)=8,~10x+y-x-(10y+x-y)=8,~9x+y-(9y+x)=8,~9x+y-9y-x=8,~8x-8y=8,~8*(x-y)=8,$

⇒x-y=1, ⇒(x,y)∈{(1,0), (2,1), (3,2), (4,3), (5,4), (6,5), (7,6), (8,7), (9,8)}.