log₂₇15-1/3*log₃5=1/3*log₃15-1/3*log₃5=1/3(log₃15-log₃5)=1/3*log₃3=1/3
x² +px +q =0 , x₁ = 9 ; x<span>₂ =11 </span>
{ p = -(x₁ + x₂) ; q = x₁*x<span>₂
</span>===
x² -( -9 +11) x + (-9)*81 = 0⇔ x² -2x -99 =0.
ответ : x² -2x -99 =0 ; || a(<span>x² -2x -99 =0) ; </span>a ≠0 ||
4(х+1)-2(х-3)=17
4х+4-2х+6=17
2х+10=17
2х=17-10
2х=7
х=7:2
х=3.5
V=пи*r^2*h;
h=V/пи*r^2;
d=1 => r=1/2;
h=пи/пи (1/2)^2;
h=4.