Answer:
163
Explanation:
If z=10 and w=7.
10z+9w [writing the equation again for reference purposes]
10(10) + 9(7) [we substitute each variable with its defined value]
100 + 9(7) [we multiply 10 and 10, aka 10 and z]
100 + 63 [we multiple 9 and 7, aka 9 and w]
163 [we add 100 and 63 to get our final answer]