Question

Решите пжл
9с^2-4a^2/18c^2d-12cd^2 при с=2/3 d=1/2

Answer 1

$frac{9c^2-4d^2}{18c^2d-12cd^2}= frac{(3c-2d)(3c+2d)}{6cd(3c-2d)}= frac{3c+2d}{6cd} \ frac{3c+2d}{6cd}=frac{3*frac{2}{3}+2*frac{1}{2}}{6*frac{2}{3}*frac{1}{2}}= frac{2+1}{2}=frac{3}{2}=1.5$