Answer:
x = 9
Step-by-step explanation:
Using the rule of exponents
[tex]a^{m}[/tex] × [tex]a^{n}[/tex] ⇔ [tex]a^{(m+n)}[/tex]
Given
[tex]11^{x}[/tex] = [tex]11^{4}[/tex] × [tex]11^{5}[/tex] = [tex]11^{(4+5)}[/tex] = [tex]11^{9}[/tex]
Since the bases on both sides are common, then equate the exponents
x = 9