## Intermediate Algebra for College Students (7th Edition)

$34$
RECALL: (1) $(a+b)(a-b) = a^2-b^2$ (2) $i^2=-1$ Use rule (1) above with $a=-5$ and $b=3i$ to obtain: $=(-5)^2 - (3i)^2 \\=25 - 9i^2$ Use rule (2) above to obtain: $=25 - 9(-1) \\=25-(-9) \\=25+9 \\=34$