1273
1)log(4)(1/√2)=-1/4
2)log(10)1=0
3)log(8)(1/√2)=-1/6
4)log(2)(1/2)=-1
5)log(3)1-log(4)1*log(5)1=0-0*0=0
1291
sin2a/[2(-cos2a)]+sina*(-cosa)/cos2a=-0,5tg2a-0,5tg2a=-tg2a
1353
ОДЗ
2x-18>0⇒x>9
x-9>0⇒x>9
log(2)[2(x-9)²]=5
2(x-9)²=32
(x-9)²=16
x-9=-4 U x-9=4
x=5∉ОДЗ U x=13