The expression is .

First group the coefficients and variables.

(– 8s³)(– 3s⁴) = (– 8 · (– 3)) (s³ · s⁴)

= (24) (s³ · s⁴)            (Multiply:  – 8 · (– 3) = 24)

Since base is common, apply the product of powers property: a^m · aⁿ = a^{m + n}.

= (24)(s^{3 + 4})

=  24s⁷                        (Add exponents: 3 + 4 = 7)

The product of (– 8s³)(– 3s⁴) is 24s⁷.