3(1,2x+3y)-2(0,3x-13y)=3,6x+9y-0,6x+26y=3x+35y
Sin^2a+cos^2a+tg^2a=1+tg^2a=1/cos^2a
Y=-3x^2-6x+2
x0=-b/2a=-(-6)/2*(-3)=-6/6=-1
y0=-3(-1)^2-6(-1)+2=-3+6+2=5
y=-x^2+x-1
x0=-b/2a=-1/2*(-1)=1/2
y0=-(1/2)^2+1/2-1=-0.25+0.5-1=-0.75
y=5x^2-10x+4
x0=-b/2a=-(-10)/2*5=10/10=1
y0=5-10+4=-5+4=-1
3х+у=14,-2х-6у=-4
3х+у=14,-6у=-4+2х
3х+у=14,у=2/3-1/3х
3х+2/3-1/3х=14
2 2/3х=14-2/3
8/3х=13 1/3
18/3х=40/3
х=40/3:8/3
х=5
3х+у=14
15+у=14
у=-1
1)4(х^2-1)
2)5(t-4st+4s)
3)c(1-27d^2)
4)vu^3(1+1)
5)(4-y)(4+y)
6)5(5q+6pq+p^2)
7)a(x^3-y^3)=a(x-y)(x^2+xy+y^2)
^- значок означает степень