R=39;⇒D=2·39=78 ⇒D=a;
<span>S=a²=78²=6084</span>
<span>(-b в степени 3) в степени 6n = (-b) в степени 18n</span>
(3x-2)/(2x+5)=(x+4)/(x-10)
(3x-2)*(x-10)=(2x+5)*(x+4)
3x^2-30x-2x+20=2x^2+8x+5x+20
x^2-45x=0
x(x-45)=0
x=0
x=45
Log²(3)(x-1)-2log(-3)(9/(x-1)=7 ODЗ x-1>0 x>1log²(3)(x-1)+2(log(3)(9)-log(3)(x-1))=7log²(3)(x-1)+2(2-log(3)(x-1))=7log²(3)(x-1)+4-2log(3)(x-1)-7=0log²(3)(x-1)-2log(3)(x-1)-3=0log(3)(x-1)=tt²-2t-3=0 D=4+12=16t1=(2+4)/2=3 t2=(2-4)/2=-1 log(3)(x-1)=3 log(3)(x-1)=-1<span> x-1=3³ x-1=27 x=28 x-1=1/3 x=4/3 </span>