Question

Hei , ajutati-ma la ex. 10,11 si 12

Answer 1

AB/4=BC/5=CA/6 (sunt direct proportionale), deci:
AB+BC+CA=90cm
4k+5k+6k =90cm
15k=90cm
90:15 =8
AB/4=4*8=32
BC/5=5*8= 40
CA/6+6*8=48
AB=32 cm
bc=40cm
CA=48cm

Answer 2

10)a)AB/4=BC/5=CA/6=k
AB/4=k⇒AB=4k
BC/5=k⇒BC=5k
CA/6=k⇒CA=6k
P=AB+BC+CA
90=4k+5k+6k
90=15k
k=6
AB=24
BC=30
CA=36

b)AB/6=BC/5=CA/7=k
AB/6=k⇒AB=6k
BC/5=k⇒BC=5k
CA/7=k⇒CA=7k
90=6k+5k+7k
90=18k
k=5
AB=30
BC=25
CA=35

11)A₁/10=A₂/12=A₃/14=k
A₁/10=K⇒A₁=10K
A₂/12=K⇒A₂=12K
A₃/14=K⇒A₃=14K
A₁+A₂+A₃=360
10K+12K+14K=360
36K=360
K=10
A₁=100
A₂=120
A₃=140

B)A₁/13=A₂/15=A₃/12=K
A₁/13=K⇒A₁=13K
A₂/15=K⇒ A₂=15K
A₃/12=K⇒ A₃=12K
A₁+A₂+A₃=360
13K+15K+12K=360
K=9
A₁=117
A₂=135
A₃=108

12)O₁/2=O₂/3=O₃/4=O₄/6=K
O₁/2=K⇒ O₁=2K
O₂/3=K⇒ O₂=3K
O₃/4=K ⇒O₃=4K
O₄/6=K ⇒O₄=6K
O₁+O₂+O₃+O₄=360
2K+3K+4K+6K=360
15K=360
K=24
O₁=48
O₂=72
O₃=96
O₄=144