X=3.5 потому что -12.7*(3.5-3.5)=0
7-2=5; 9-7=2; а-1; 5-а; 50-40=10; а-30; 20-10=10
1)-5/18+(-1/6)=-5/18-1/6=-4/9
2)(-4 1/6)/-5/6=(-2 1/3)/-5/12=(-2/3)/-5/12=8/5
Log3<span> 18/(2+log</span>3<span> 2)=(log</span>3<span> 2 + log</span>3<span> 9)/(2+log</span>3<span> 2)=(log</span>3<span> 2+2)/(2+log</span>3<span> 2)=1
</span>