-7x+4=0,5x+9
-7x-0,5x=9-4
LogbA*logaB=1
logcA/logcB+logcB/logcA=1
logcAB/logcBA=1
1=1
(x-2)*(x+5)=8
x2+5x-2x-10-8=0
x2+3x-18=0
D=b^2 -4ac = 3^2 -4 +1 +(-18)= 9+72=81
x1,2 = -b+- корень из D / 2a
x1,2= -3 +- 9 / 2
x1= 3
x2=-6
2x+4/x×2-x-x-4/x×2+x=0
2x-x-x+x=0
x=0
Ответ: x=0