## Algebra: A Combined Approach (4th Edition)

$61$
Step 1: $(6+5i)(6-5i)$ Step 2: $6(6)+6(-5i)+5i(6)+5i(-5i)$ Step 3: $36-30i+30i-25i^{2}$ Step 4: $36-25i^{2}$ Step 5: Since $i^{2}=-1$, we get $36-25(-1)$. Step 6: $36+25$ Step 7: $61$