Răspuns :
[tex]a - b = 6[/tex]
[tex]xa - xb + 9a - 9b = 654[/tex]
[tex]x(a - b) + 9(a - b) = 654[/tex]
[tex]x\times 6 + 9 \times 6 = 654[/tex]
[tex]6(x + 9) = 654 \: | \div 6[/tex]
[tex]x + 9 = 109[/tex]
[tex]x = 109 - 9[/tex]
[tex]x = 100[/tex]
[tex]xa - xb + 9a - 9b = 654[/tex]
[tex]x(a - b) + 9(a - b) = 654[/tex]
[tex]x\times 6 + 9 \times 6 = 654[/tex]
[tex]6(x + 9) = 654 \: | \div 6[/tex]
[tex]x + 9 = 109[/tex]
[tex]x = 109 - 9[/tex]
[tex]x = 100[/tex]
xa-xb +9a-9b =654
x(a-b ) + 9(a-b ) =654
x*6 + 9*6 = 654
6x =654- 54
6x =600
x =100