x>=arccos(60 градусов)/2+πk, k∈z
x>=π/6+πk, k∈z
3-2x=0
-2x=-3|:(-2)
x=3/2
x=1,5
Ответ:1,5
Удачи)
3(a³-b³)+5(a²-b²)=3[a-b][a²+ab+b²] +5(a-b)(a+b) = (a-b)(3a²+3ab+3b²+5a+5b)
(2.5a -3y)² =6.25a² -2*2.5a *3y +9y² =6.25a²-15ay+9y²
(5x +7.5n)² =25x² + 2*5x*7.5n +56.25n² = 25x² +75xn +56.25n²
(25a2-40ab+16b2)-(21a2-48ab-7ab+16b2)=25a2-40ab+16b2-21a2+48ab+7ab-16b2=4a2+15ab