Раскройте скобки (2t+1)^2 (K^2-5y)^2 (7c+3)(7c-3)

Question

Раскройте скобки (2t+1)^2

(K^2-5y)^2

(7c+3)(7c-3)

Answer 1

(2t+1)^2=4t^2+4t+1; (k^2-5y)^2=k^4-10k^2*y+25y^2; (7c+3)(7c-3)=49c^2-9.