Answer:
f=41, 41×(-8)=-328(not so sure so you might want so check with other people again)
Step-by-step explanation:
f(x)=12x-29
Step 1, u bring the x terms over to one side, in this case on the left side. So it becomes:
f(x)-12x=29
Next step is to find the common factor of the x terms
f(x)-12(x)=29
f-12=29
bring the numbers to the right side
f=29+12
so f=41