2)
a)
2(2x+1)=3(x+4)
4x+2=3x+12
4x-3x=12-2
x=10
b)
{m(A),m(B),m(C)} dp {2,3,5}
m(A)=2k
m(B)=3k
m(C)=5k
2k+3k+5k=180
10k=180
k=18
m(A)=2*18=36
m(B)=3*18=54
m(C)=5*18=90
Triunghi dreptunghic
c)
Dreptunghic isoscel
d)
h=5/6*l=5/6*12=5*12/6=10 cm
A=l*h/2=12*10/2=60 cm^2
3)
a)
2-3x=10-4x
-3x+4x=10-2
x=8
b)
|x+1|=6
Cazul 1:
x+1=6
x=6-1
x=5
Cazul 2:
x+1=-6
x=-6-1
x=-7
