Question

C+d-3c^2+3d^2 разложите на множители

Answer 1

$c+d-3c^2+3d^2=c+d-3(c^2-d^2)=(c+d)-3(c+d)(c-d)= \\ (c+d)(1-3(c-d))=(c+d)(1-3c+3d)$