evaluate the expression when b=5

Answer:
9. [tex]35^{2}[/tex] or 1225
12. [tex]15^{2}[/tex] or 225
Step-by-step explanation:
Put 5 instead of b
9. [tex](7b)^{2}[/tex]
= [tex](7 * 5)^{2}[/tex]
= [tex]35^{2}[/tex] or 1225
12. [tex](3b)^{2}[/tex]
= [tex]( 3 * 5)^{2}[/tex]
= [tex]15^{2}[/tex] or 225