7^(x+2)-14*7^x=5
7^x*(49-14)=5
7^x*35=5
7^x=5/35=1/7
x=-1
18,2:(-9,1)*0,7-3,4*(2-3):17=(18,2:(-9,1)*0,7)-(3,4*(-1):17)=-14-(-0,2)=-14+0,2=-13,8
1
log(2)m+log(2)n=9+5=14
2
log(3)m-log(3)9-log(3)n=13-2-7=4
3
3/5*log(5)b=0,6*(-2)=-1,2
4
-1/4*log(9)m=-1/4*(-4)=1
5
25^(1/2log(81)5)=25^1/log(81)25)=25^log(25)81=81
6
1/4*(1/2)^log(1/2)14=1/4*14=3,5
<span>(0,5x^2-3xy)+(3xy-x^2+2)=0,5х^2-x^2+2=-0.5x^2+2
-0.5*2^2+2=-2+2=0
</span>