Answer :
dahello
to solve this question, we simply solve for the first expression and then compare with the options given
[tex]7^8\times7=7^9[/tex]now we look for options whose expressions is equal to 7^9
with option A
[tex]7^3\cdot7^3=7^{(3+3)}=7^6[/tex]option A is not equivalent to the given expression
option B
[tex]\frac{7^{18}}{7^9}=7^{(18-9)}=7^9[/tex]option B is equivalent to the given expression
next we check option C
[tex](7^3)^3=7^{3\cdot3}=7^9[/tex]option C is equivalent to the given expression
next is option D
[tex]7^4+7^5\ne7^9[/tex]option D is not equivalent to the given expression
lastly we check option E
[tex]7^4\cdot7^5=7^{(4+5)}=7^9[/tex]option E is equivalent to the given expression
from the options given, only option B, C and E are equivalent to the given expression.