1)(3·c·q³·q²·q³·q²·q²·b²)/(54·q²·q²·q³·q·b·b³·b²·b³·b)=(3·c·q³·q²)/(54·q·b·b³·b³·b)=(3·c·q³·q·q) /(3·18·q·b³·b³·b²)=(c·q³·q)/(18·b³·b³·b²)
2)(18mn-27m)/9mn=(9m(2n-3))/9mn=(2n-3)/n
3)(3c+15)/(c²-25)=3(c+5)/(c-5)(c+5)=3/(c-5)
4)(x²-14x+49)/(49-x²)=(x-7)(x-7)/(7-x)(7+x)=(x-7)/(x+7)