Log(7) 9+log(7) 2401-log (7) 73

Решите задачу:

$1)log_7 9 +log_7 7^4 -log_7 63=log_79 -log_7 63 +4log_7 7= \\ \\ =log_7 \frac{9}{63} +4*1=log_7 \frac{1}{7} +4=log_7 7^{-1} +4= \\ \\ =-1*log_7 7 +4=-1*1+4=3 \\ \\ \\ 2) \left \{ {{4x+y=3} \atop {3x-2y=5}} \right. \ \ \left \{ {{y=3-4x} \atop {3x-2(3-4x)=5}} \right. \\ 3x-6+8x=5 \\ 11x=11 \\ x=1 \\ \\ y=3-4x=3-4*1=-1 \\ OTBET: (1;-1) \\ \\ \frac{5(x+y)}{x-y} = \frac{5(1-1)}{1+1} =0 \\ \\ OTBET: 0$