5x-4y=13
2x-y=4 /*4⇒8x-4y=16
отнимем
-3х=-3
х=1
2-у=4
у=-2
(1;-2)
4х^2-5,
х= 0,5
4*(0,5)^4- 5=-4
2cos(x/3+π/4)-√3=0
cos(x/3+π/4)=√3/2
x/3+π/4=-π/6+2πk U x/3+π/4=π/6+2πk
x/3=-5π/12+2πk U x/3=-π/12+2πk
x=-5π/4+6πk U x=-π/4+6πk,k∈z
tg(-x/7)=-1
-tgx/7=-1
tgx/7=1
x/7=π/4+πk
x=7π/4+7πk,k∈z
(5-3х)(х-1)<-1
5x-3x^2-5+3x+1<0
-3x^2+8x-4<0
3x^2-8x+4>0
3x^2-6x-2x+4>0
3x(x-2)-2(x-2)>0
(x-2)(3x-2)>0
x-2>0 x-2<0
3x-2>0 3x-2<0
x>2 x<2
3x>2 3x<2
x>2 x<2
x>2/3 x<2/3
<span>x>2</span> <span>x<2/3</span>
Ответ:
.