Markup means they sell it for that percentage more than they bought it for. First let's calculate how much they will mark it up for:

Convert 87% into a decimal(87/100):

Multiply:

This is how much they'll mark it up, now let's add it to how much they bought it for to find out the selling price:
Step-by-step explanation:
Atmost means less than 45:
Let us assume number is x
x<45(at most)
Atleast means more than 45:
x>45
Answer:
x= -1
y=2
Step-by-step explanation:
6x+5y=4
6x-7y=-20
Subtract
Answer:
D
Step-by-step explanation: