[tex]x\ =\ \frac{b}{2}+y\\\\\frac{1}{2} b + y = x/+(-y)\\\\\frac{1}{2} b = x-y /:\frac{1}{2} \\\\b = 2x-2y[/tex]
Odpowiedź:
x = b/2 + y | · (2 + y)
x · (2 + y) = b
2x + xy = b