Răspuns:
1)
(2x-3)/5-(x+1)/2<=(x-3)/10
[2*(2x-3)-5*(x+1)]/10<=(x-3)/10 | *10
4x-6-5x-5<=x-3
-x-11<=x-3
x+x>=+3-11
2x>=-8
x>=-4
S=(-4;+infinit)
2)
x^2-y^2=297=>(x-y)(x+y)=297 (1)
x-y=11 (2)
Din (1) si (2) => 11*(x+y)=297=>x+y=297/11=>x+y=27
3)
P(-8;-6) O(0,0)
d(P,O)=radical[(xp-xo)^2+(yp-yo)^2]=radical[(-8-0)^2+(-6-0)^2]=radical(64+36)=radical(100)=10
4)
A=[(AB^2-CD^2)*tg(ABC)}/4=>80=[(28-12)*(28+12)*tg(ABC)]/4
80=(16*40*tg(ABC)]/4=>80=160*tg(ABC)
tg(ABC)=80/160=1/2
5)P=6*a=> 36=6*a=> a=36/6=6
R=a=6
A=pi*R^2=36pi
Explicație pas cu pas:
