simplify the following quotient of complex numbers into the form of a+bi -9+8i/1+2i

When there is a division (denominator), multiply top and bottom by the conjugate of the denominator.

-9+8i
-----
1+2i
(-9+8i)(1-2i)
=---------------
(1+2i)(1-2i)
(-9+16+8i+18i)
=----------------
(1+4-2i+2i)
(7+26i)
=---------
(5)
=7/5 + (26/5)i