Помогите пожалуйсто срочо!!!!!!

$1)Log_{4}(5-x)=2 ; Log_{4}(5-x)= Log_{4}16; 5-x=16;-x=11;x=-11$
$2)Log_{2} (4+x)=2; Log_{2} (4+x)= Log_{2}4; 4+x=4;x=0$
$3)Log_{7} (9-x)= Log_{7} 8; 9-x=8; x=1$
$4) Log_{7} (8+x)= Log_{7}10; 8+x=10; x=2$
$5) Log_{7}(x+9)= Log_{7} (5x-7); x+9=5x-7; -4x=-16;x=4$
$6) Log_{ \frac{1}{2} } (13-x)=-4; Log_{ \frac{1}{2} } (13-x)= Log_{ \frac{1}{2} }16; 13-x=16; x=-3$
$7) Log_{2}(18-6x)=4 Log_{2}3 ;18-6x= 3^{4};-6x=81-18; -6x=63;x=$ -10.5
$8) Log_{4} ( x^{2}-4x)= Log_{4}( x^{2}+3); x^{2}-4x-x^{2}-3=0;-4x=3;x=$ -0.75
$9) Log_{2}(4+x)= Log_{2}(2-x)+2; Log_{2}(4+x)= Log_{2}(2-x)+ Log_{2}4;$ $Log_{2}(4+x)= Log_{2}4(2-x); 4+x=8-4x; 5x=4; x=0.8$
10) $10) Log_{x-3}81=4; Log_{x-3}81= Log_{x-3} (x-3)^{4}; 3^{4}= (x-3)^{4};x=6$
$11) Log_{16} 2^{5x-6}=4; Log_{16} 2^{5x-6}= Log_{16} 16^{4}; Log_{16} 2^{5x-6}= Log_{16} 2^{16};$ $5x-6=16;5x=22;x=4.4$
12) $2^{ Log_{4} (2x+5) }=3; 2^{ Log_{2}3 } ; Log_{4}(2x+5)= Log_{4} 9;2x=9-5;2x=4;x=2$
хух, дописал.