1 5c b 1 5c b. 3a2+12ab+12b2. 5a+5b6b2. (A^-3*B^2/2c)^2*(2c)^3*a^6/b^5. 3b 5a-7b. 2b/1-b^2 +1/1-b. 1/(1+A/B)=1-A/B при a<