A local shoe store buys shoes at a wholesale price and then marks them up 80% to calculate the retail price. The wholesale price varies, depending on the quantity of shoes purchased. Write an equation that could be used to find the retail price for each range. How do you know the equation will work consistently for each range?

In this question, the buying price will be lower if the quantity bought is higher. But the markup ratio for retail price is constant at 80% of buying price. If the price of the range is x, then the equation of retail price would be:

Retail price= x * (100%+80%)

Retail price= x * 180%=

Retail price= 1.8 x

The equation should be same because the markup ratio is same. Only the buying price that will be different based on the quantity of shoe purchased.

for this case we have by definition, if two lines are perpendicular, then the product of their slopes is -1.

then, given the following line:

so,

we are looking for m_ {2}:

then, the line is given by:

we find "b" replacing the given point:

finally, the equation is:

option c

the awnser is visionary