What is the complex conjugate of $-3+7i$?

Find the product $(-1+3i)(4+5i)$ and give the answer in $a+bi$ form.

Rationalize and simplify $\frac{3}{2-5i}$, and express the result in standard form $a+bi$ in lowest terms.

Find $i^{1000}$ using the fastest method.

Which sequence of steps is the correct general procedure to divide the complex numbers: $(a+bi)÷(c+di)$?