How do you multiply #\frac { 4z ^ { 2} + 24z } { 3z ^ { 2} - 9z - 12} \cdot \frac { z ^ { 2} - 4z - 5} { z - 4} #?

2 Answers

Perhaps some one else can spot how to simplify this further.

#(4z(z^2+z-30))/(3(z-4)(z-4))#

Explanation:

Just playing with formats to start with. Looking for things to cancel out.

#(4z(z+6))/(3(z^2-3z-4))xx((z+1)(z-5))/(z-4)#

#(4z(z+6))/(3(z+1)(z-4))xx((z+1)(z-5))/(z-4)#

#(4z(z+6))/(3cancel((z+1))(z-4))xx(cancel((z+1))(z-5))/(z-4)#

#(4z)/3xx((z+6)(z-5))/((z-4)(z-4)#

#(4z)/3xx(z^2+z-30)/((z-4)(z-4)#

#(4z(z^2+z-30))/(3(z-4)(z-4)#

Dec 22, 2016

#(4z(z+6)(z-5))/(3(z-4)(z-4))#

Explanation:

#(4z^2+24z)/(3z^2-9z-12)*(z^2-4z-5)/(z-4)#

#(4z(z+6))/(3(z^2-3z-4))*((z+1)(z-5))/(z-4)#

#(4z)/3*((z+6))/((z+1)(z-4))*((z+1)(z-5))/((z-4))#

#(4z(z+6)(z-5))/(3(z-4)(z-4))#