(3uaybzc)(-yfzg)
Move yf.
3ua(yfyb)zc(-1zg)
Use the power rule aman=am+n to combine exponents.
3uayf+bzc(-1zg)
3uayf+bzc(-1zg)
Move zg.
3uayf+b(zgzc)⋅-1
Use the power rule aman=am+n to combine exponents.
3uayf+bzg+c⋅-1
3uayf+bzg+c⋅-1
Multiply -1 by 3.
-3uayf+bzg+c
Simplify (3u^ay^bz^c)(-y^fz^g)