Respuesta :
Go back to your power laws.
When dividing exponents with like bases, you keep the base and subtract the exponents:
a^4 / a^11 = a^(4-11) = a^(-7)
When dividing exponents with like bases, you keep the base and subtract the exponents:
a^4 / a^11 = a^(4-11) = a^(-7)