Answer:
Options : B & D
Explanation:
E(x) = 10x - 30 , where x is the number of doors she knocks
Given she has to pay her own expense.
So whatever she earns $30 is reduced from it ,for her expense.
Option A: She can earn $10 even if she does not knock
any doors - False
That is, x = 0
When x = 0 , E (x) = 10 ( 0 ) - 30 = - 30
=> she loses $30.
Option B :Her expenses are $ 30 per week - True
E(x) = 10x - 30
Expenses are reduced from her earnings.
Option C: She will lose $10 per week if she does not knock
any doors - False.
Already checked on option A that if she does not knock
on any door, means x = 0 , then loses $30.
Option D : If she does not knock on any doors at all during
the week , she will lose $30 - True