Răspuns:
a=0, b=0
Explicație pas cu pas:
Daca C=o=> cele doua fractii sunt egale=>
(5a-2b)x(7a+b)=(3a-b)x(5a+2b)
35a^2+5ab-14ab-2b^2=15a^2+6ab-5ab+2b^2
33a^2-2b^2-9ab=17a^2+2b^2+ab
33a^2-2b^2-9ab-17a^2-2b^2-ab=0
16a^2-4b^2-8ab=0
Daca b=2a
16a^2-4x2a^2-8ax2a=0
16a^2-8a^2-16a^2=0
-8a^2=0/(-1)
8a^2=0
a^2=0
a=0