Answer:
The equation for this is: 
Step-by-step explanation:
We have that the number though is n.
Adds 10:
This means that now we have: 
Multiplies by 3:
This means that now we have: 
Gets 42:
This means that: 
B. 1/4(n - 64)
Multiplying n and -64 by 1/4 leaves you with 1/4n - 16, the original equation.
Answer:
0
Step-by-step explanation:
The opposite of 12 is -12, and 12+(-12)=12-12, or 0.
Step 1 remove paranthesis
(-30a-105)=-15
Step 2: Move constant to RHS (take not negative sign is removed if sides are changed and vice versa)
-30a=-15+105
-30a=90
Step 3: Simplify
-a=3
Step 4: remove negative sign from variable
a=3