Question

(3d+5c)и все это в квадрате-(3d-5с)и все это в квадрате.упростите 

Answer 1

(3d+5c)^2-(3d-5c)^2 = ((3d+5c)-(3d-5c))((3d+5c)+(3d-5c))=(3d+5c-3d+5c)(3d+5c+3d-5c)=

=10c*6d = 60cd