Răspuns:
A. Rationalizam 5^3cu^5 a/3=^15 a=3^15
B.rationalizam 4+^2. ^2+2/a=^2(4-^2)/14=^2+2/a=4^2-2/14=^2+2/a=2(2^2-1)/14=simplific 14 cu 2 =^2+2/a=2^2-1/7 (^2+2)*7=(2^2-1)a ,(2^2-1)a=(^2+2)*7. , a=(^2+2)*7/2^2-1. a=7^2+14/2^2-1. Rationalizam. a=(7^2+14)*(2^2+1)/7. a=7(^2+2)*(2^2-1)/7. 7simplif.a=(^2+2)*(2^2+1). a=4+^2+4^2+2. a=6+^2+4^2. a=6+5^2,
