18a+15a=3а(6+5)=3а·11=33а или 18a+15a=а(18+15)=а·33=33а
32b-17b=b(32-17)=15b
54c-c=54c-1c=c(54-1)=53c
d+80d=1d+80d=d(1+80)=81d
38x+12+7=38x+(12+7)=38x+19=19(2x+1)
60+25y-14y=60+(25y-14y)=60+(y(25-14))=60+11y
8z-8+5z=(8z+5z)-8=(z(8+5))-8=13z-8
5m+2n-3m+5t=(5m-3m)+2n+5t=(m(5-3))+2n+5t=(2m+2n)+5t=2(m+n)+5t