1) 12a²b²:(3ab²) a=3/4 b=1/9
12a²b²:(3ab²) =4a=4*3/4=3
2) (-49m³n^4):(7mn^4) m=1/7 n=1
(-49m³n^4):(7mn^4)=-7m²=-7*(1/7)²=-7/49=-1/7
3) (4a³b+6a²b):(2ab²) a=-1 b=5
(4a³b+6a²b):(2ab²) =2ab(2a²+3b):(2ab²)=(2a²+3b):b=(2*1+3*5)/5=17/5
4)(12a^{4}-24a³+12a³):(6a²) a=1/4
(12a^{4}-24a³+12a²):(6a²) =6a²(2a²-4a+2):(6a²)=2a²-4a+2=2/16-1+2=1/8+1=9/8