Answer:
![=15.4z-12](https://img.qammunity.org/2021/formulas/chemistry/high-school/epw5cdr2pqh4vgjt2o6cfvurwqujreez11.png)
Step-by-step explanation:
The initial expression that we have in this problem is
![7.4z-5(-1.6z+2.4)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/ijurnitj8eh8ml2th1z3i7wy1mdepmh8ot.png)
First of all, we multiply the -5 by all the terms in the brackets. Doing so, we get the following expression:
![7.4z-5(-1.6z)-5(2.4)=7.4z+8z-12](https://img.qammunity.org/2021/formulas/chemistry/high-school/sytf5las8mhapnwq1k4i5nbprt1ti3ad26.png)
Now we can combine the like terms, which are the terms having the same variable.
Here the like terms are:
![7.4z, 8z](https://img.qammunity.org/2021/formulas/chemistry/high-school/cgqfpb7553gd3m5y8efkkmux6fb7xfrat0.png)
and
-12
Combining the first 2 terms we get
![7.4z+8z=15.4 z](https://img.qammunity.org/2021/formulas/chemistry/high-school/imaxrlp0j9rfc181obrr6noqtr62uz0cs9.png)
Therefore, the final expression overall is:
![=15.4z-12](https://img.qammunity.org/2021/formulas/chemistry/high-school/epw5cdr2pqh4vgjt2o6cfvurwqujreez11.png)