Question

$left { {{x-y=2} atop {3^x-3^y=24}} right$

Answer 1

x=y+2

Подставим это во второе уравнение:

$3^{y+2}-3^y=24\ 9cdot3^y-3^y=24\ 8cdot3^y=3cdot8\ 3^y=3\ y=1\x=y+2=3$

Answer 2

$left { {{x-y=2} atop {3^x-3^y=24}} right\left { {{x=2+y} atop {3^{2+y}-3^y=24}} right\left { {{x=2+y} atop {3^y(3^2-1)=24}} right\left { {{x=2+y} atop {3^ycdot8=24}} right\left { {{x=2+y} atop {3^y=3}} right\left { {{y=1} atop {x=3}} right$