1)1)2xˇ2-9x+5=(x-3)ˇ2,2xˇ2-9x+5 = xˇ2-6x+9,xˇ2-3x-4=0,(x-4)(x+1)=0
a)x-4=0, x=4
b)x+1=0,x=-1
1)2)log (2x-4)ˇ2-log(9-x)=log (3ˇ2)
(2x-4)ˇ2/(9-x)=9,(2x-4)ˇ2 = 9.(9-x),4xˇ2-16x+16=81-9x
4xˇ2-7x-65=0 ,kvadratičnoe uravnenie
1)3) 3.3ˇx+3ˇx = 108,4.3ˇx = 108, 3ˇx=27, 3ˇx = 3ˇ3, x=3
2)Icpolzujeme formuly: sin2a=2.sina.cosa , sinˇ2x + cosˇ2x = 1
(2.cosa-2.sina.cosa)/1-sina = 2cosa(1-sina)/(1-sina)=2.cosa