Question

URGENT!!!DAU COROANĂ!!!!HELP!!!!​

Answer 1

scriem numerele in baza 10

(10a+b)/4=(10b+a)/7

7(10a+b)=4(10b+a)

70a+7b=40b+4a

66a=33b

a/b=33/66=3/6=1/2

deci

a=1 si b=2

numarul ab=12

2.

a-portocala

b-mandarina

c-mar

a+b+c=30

a/30=1/5 ⇒5a=30 ⇒a=6 portocale

(a+b)/30=1/3

3(a+b)=30

a+b=10

6+b=10

b=4 mandarine

30-6-4 =20 mere