what is -2.3 times 10 to the 13th power multiplied by 0.8 times 10 to the negative 28 power

Thank you!

(-2.3·10^13)·(0.8·10^-28)

=  (-2.3·0.8)·(10^13·10^-28)        Rearrage, since you can multiply in any order.

=  (-1.84)·(10^-15)                        When you multiply numbers with the same base, just add exponnents.

=  -1.84 · 10^-15