Q=a2/a1
q=-1/3:1/9=-1/3*9/1=-2
an=a1*q^(n-1)
an=1/9*(-3)^(n-1)
-4x=-12-3
-4x=-15
x=-15:(-4)
x=3.75
A^2+b^2=(a+b)^2-2ab=49-24=25
128^8/32^11=(2^7)^8/(2^5)^11= 2^56/2^55=2
<span>6sin30° - 2ctg45 ° - cos0° = 6</span>·0,5 - 2·1 - 1 = 3 - 2 - 1 = 0
Ответ: 0.