In 7(cy^2+dy-3)=14y^2-7y+f, what are the values of c, d and f?
\(7(cy^2+dy-3) = 14y^2-7y+f \\ 7cy^2+7dy-21 = 14y^2-7y+f\\ 7cy^2=14y^2 \\ c=2 \\ 7dy=-7y\\ d=-1\\ -21=f \)
