Question

Fie paralelogramul ABCD cu perimetrul de 120 cm. Afla laturile lui daca AB = AD×4+5​

Answer 1

P=2(L+l) Semiperimetrul=P:2=L+l
Semiperimetrul=120 cm:2=60 cm ⇒ L+l=60 cm AB=CD; BC=AD
a) AB+BC=60 BC=60-28; BC=32 cm R:32 cm si 28 cm

b) AB=2×BC; 2BC+ BC=60; 3BC=60 |:3; BC=20 cm; AB=60-20; AB=40 cm R: 40 cm si 20 cm

c) AB=AD-8; AD-8+AD=60 |+8; 2AD=68 |:2; AD=34 cm; AB=34-8; AB=26 cm R: 34 cm si 26 cm

d) BC=AB/3 ⇒ AB=3·BC BC+AB=60 BC+3·BC=60; 4·BC=60 ; BC=60:4; BC=15 cm; AB=3·15, AB=45 cm R:45 cm si 15 cm

e) AB=AD×4+5; AD×4+5+AD=60; 5AD+5=60 |-5; 5AD=55 |:5; AD=11 cm; AB=60-11; AB=49 cm R: 49 cm si 11 cm

f) BC=20% din AB ⇒ AB+20AB/100=60; 100AB/100+20AB/100=60; 120AB/100=60; 120AB=100×60; 120·AB=6000 |:120; AB=50 cm; BC=60-50; BC=10 cm R: 50 cm si 10 cm

Sper ca te am ajutat,coroana?

Answer 2

Răspuns:

Explicație pas cu pas:

AB + AD = 120 : 2 = 60 cm

AB = 4AD + 5

4AD + 5 + AD = 60 cm

5AD = 60 - 5 = 55 cm

AD = 55 : 5 = 11 cm

AB = 4*11 + 5 = 49 cm

AB = CD

AD = BC