(√2сosa-2cosπ/4cosa-2sinπ/4sina)/(2sinπ/6cosa+2cosπ/6sina-√3sina)=
=(√2cosa-2*√2/2*cosa-2*√2/2*sina)/(2*1/2*cosa+2*√3/2sina-√3sina)=
=(√2cosa-√2cosa-√2sina)/(cosa+√3sina-√3sina)=-√2sina/cosa=-√2tga
4*a/(3*c)-(16*a²+9*c²)/(12*a*c)+(3c-16a)/(4*a)=(16a²-16a²-9c+9c²-48*a*c)/(12a*c)=
=-48*a*c/(12*a*c)=-4.
7(2х+у)-5(3+у)=6
14х+7у-15-5у=6
7у-5у=6+15-14х
2у=21-14х
у=21-14х
--------
2
у=10,5-7х
X^2-16+64=01)х^2=-12-36
x^2=-48
2)4x^2-28x+49=0
D=b^2-4ac=28^2-4*4*49=0
x=-b/2a=28:2*4=28:8=3.5
3)<span>x^2=16-64
x^2=-48
4)</span><span>9x^2+30+25
</span><span>9x^2=-30-25
</span><span>9x^2=-55
</span>x^2=-55/9
x^2=-6целых 1/9
2sinx=1
sinx=1/2
x=(-1)^k*arcsin1/2+πk , k∈Z
x=(-1)^k*π/6+πk , k∈Z
Ответ:(-1)^k*π/6+πk , k∈Z