15x+25y / 5x= 5(3x+5y) / 5x= 3x+5y / x
5cx-5cy / 15cz= 5c(x-y) / 15cz= x-y / 3z
abc+abd / abcd= ab(c+d) / abcd= c+d / cd
6abs / 2as+4bs= 2s(3ab) / 2s(a+2b)= 3ab / a+2b
axy+5ay / abz+5az= a(xy+5y) / a(bz+5z)= xy+5y / bz+5z
bc+bd / 3c+3d= b(c+d) / 3(c+d)= b / 3