Answer:
5
Step-by-step explanation:
(2x + y) - z
Let x=3 y=4 and z=5
2*3 +4 -5
Multiply and divide first
6 +4 -5
Then add and subtract
10-5
5
Answer:
15
Step-by-step explanation:
The given equation is


When we multiply we obtain the equations:


We add both equations to obtain:

Divide both sides by -7 to get:

Answer:
Frieda's work is correct.
Step-by-step explanation:
z+22= 64 can also be z= 64-22
64-22= 42
Meaning, z= 42
42+22-22= 64-22
42= 42