1)
a) y(x+6)-3(x+6)=(y-3)(x+6)
b)x²-4x+4=(x-2)²=(x-2)(x-2)
2)
a) 5(x+2)-2(2x+3)=34-5x
5x+10-4x-6=34-5x
x+4=34-5x
6x=30
x=5
b) [tex] \frac{x+4}{5}- \frac{2}{3} = \frac{x-8}{3} [/tex] |*15
3(x+4)-5*2=5(x-8)
3x+12-10=5x-40
2x=42
x=21
3) notezi cu O intersectia diagonalelor
AO=AC/2=12cm
BO=BD/2=9 cm
AB²=AO²+BO²
AB²=144+81=225
AB=√225=15 cm
b) P=4*l=4*AB=4*15=60 cm
A=d1*d2/2=24*18/2=216 cm²
