47. Чему равен корень уравнения: 1) 2x/3 + 5x/4 = 23; 2) x/6 − x/8 = 7/36; 3) 8x/10 − 4/15 = x/6?

1. $\backslash (\backslash frac\{8x+15x\}\{12\}\backslash )=23$; $23x=276$; $x=12$.
2. $\backslash (\backslash frac\{x\}\{24\}\backslash )=\backslash (\backslash frac\{7\}\{36\}\backslash )$; $x=\backslash (\backslash frac\{14\}\{3\}\backslash )$.
3. Умножим на 30: $24x-8=5x$; $19x=8$; $x=\backslash (\backslash frac\{8\}\{19\}\backslash )$.

Ответ: 1) 12; 2) 14/3; 3) 8/19.