laws of exponent : multiplication and power to a power simplify

the whole expression is a multiplication
we must group what we can multiply
[tex](4\times-3)(r^4\times r\times r)(s^{-2}\times s^{-3}\times s)[/tex]when multiply equal terms the exponents are added
so
[tex](-12)(r^{4+1+1})(s^{-2+(-3)+1})[/tex]do the sum and the final expression is
[tex]-12r^6s^{-4}[/tex]