Answer:
[tex]\frac{z-2}{z+4},z\ne-4[/tex]
Step-by-step explanation:
The given quotient is
[tex]\frac{z^2-4}{z-3}\div \frac{z+2}{z^2+z-12}[/tex]
Multiply by the reciprocal of the second fraction;
[tex]\frac{z^2-4}{z-3}\times \frac{z^2+z-12}{z+2}[/tex]
Factorize the numerators;
[tex]\frac{z^2-2^2}{z-3}\times \frac{z^2+4z-3z-12}{z+2}[/tex]
[tex]\frac{(z-2)(z+2)}{z-3}\times \frac{z(z+4)-3(z+4)}{z+2}[/tex]
[tex]\frac{(z-2)(z+2)}{z-3}\times \frac{(z-3)(z+4)}{z+2}[/tex]
Cancel out the common factors;
[tex]\frac{(z-2)(1)}{1}\times \frac{(1)(z+4)}{1}[/tex]
[tex]\frac{z-2}{z+4},z\ne-4[/tex]