Question

Va rog frumos rpd .......

Answer 1

Răspuns:

a) AB=16 cm; BC=6,4dm=64cm; CD=32 cm, DE=8cm

$\frac{DE}{AB}=\frac{8}{16}=\frac{1}{2}$  (1)  

$\frac{CD}{BC}=\frac{32}{64} =\frac{1}{2}$  (2)

(1), (2) ⇒ $\frac{DE}{AB}=\frac{CD}{BC}$

b) AB=2cm; BC=30 cm;  $\frac{CD}{DE}=15$

$\frac{BC}{AB} =\frac{30}{2} =15$ ⇒ $\frac{CD}{DE}=\frac{BC}{AB}$

c) AB=$\frac{8}{3}$ dm;   BC=0,(6) dm =$\frac{6}{9}$ dm=$\frac{2}{3}$ dm;  CD=20‰ DE

$CD=\frac{20}{1000} *DE=\frac{2}{100}*DE$ ⇒ $\frac{CD}{DE} =\frac{2}{100}=\frac{1}{50}$  (1)

$\frac{BC}{AB}=\frac{2/3}{8/3} =\frac{2}{8} =\frac{1}{4}$ (2)

(1), (2) ⇒ $\frac{CD}{DE}\neq \frac{BC}{AB}$

D) AB=56 cm; BC=28 cm; CD=3,5 cm; DE=7 cm

$\frac{BC}{AB}=\frac{28}{52} =\frac{1}{2}$  (1)

$\frac{CD}{DE}=\frac{3,5}{7} =\frac{1}{2}$ (2)

(1), (2) ⇒ $\frac{BC}{AB} =\frac{CD}{DE}$

Explicație pas cu pas: