Answer
-6.4$a^{4}$$b^{2}$
Work Step by Step
(-4ab)(1.6$a^{3}$b) =
Use the exponent rule to simplify: $b^{n}$ $b^{m}$ = $b^{m+n}$
(-4) $\times$ 1.6 $\times$ $a^{1+3}$ $\times$ $b^{1+1}$ =
-6.4 $\times$ $a^{4}$ $\times$ $b^{2}$ =
-6.4$a^{4}$$b^{2}$
