Question

ajutorrrr
va rog sa ma ajutati

Answer 1

2(x+1)+(x+6)+(3x-2)+2(2x-3)=40 m
2x+2+x+6+3x-2+4x-6=40m
2x+2+x+6+3x-2+4x-6=40m
10x=40m
x=4m
AB=2(x+1)=2(4+1)=2*5=10m
BC=(x+6)=4+6=10m
CD=(3x-2)=3*4-2=10m
DA=2(2x-3)=(2(2*4-3)=10m
O intersectia diagonalelor
AO=√10²-(12/2)²=√64=8m
A=12x8/2 *2=96 m²


3.O piata in forma de triunghi cu perimetrul de 30 dam are lungimile laturilor egale cu (x+7) dam, (2x+4) dam, respectiv (3x+1) dam. Calculati aria pietei .
x+7+2x+4+3x+1=30
6x=30-12
x=18:6=3 m
x+7=3+7=10
2x+4=2*3+4=10
3x+1=3*3+1=10
triunghiul este echilateral
A=L²√3/4=10²√3/4=100√3/4=25√3 dam

4. Un teren de tenis in forma de dreptunghi de dimensiune Lsi l are aria egala cu 160 m la puterea 2 .Stiind ca L=(x+6)m si l (x-6) m,x mai mare decat 6,Calculati perimetrul terenului de tenis.

[2(x+6)][2(x-6)]=160 m²
(2x+12)(2x-12)=160 m²
4x²-144=160
x²=(160+144)/4
x=√76m=2√19≈8,717 m
L=2√19+6=14,717 m
l=2√19-6=2,717 m
P=2(L+l)=2(2√19+6+2√19-6)=2*4√19=34,87 m