# How do you multiply (7i)(6i)(-3-5i)?

$126 + 210 i$
Multiplying $7 i \cdot 6 i$ we get $42 {i}^{2} = - 42$ (recall that ${i}^{2} = - 1$)
Now multiply $- 42 \left(- 3 - 5 i\right)$, which equals $126 + 210 i$