Answer:
pairs
Step-by-step explanation:
Given
Profit on selling 'x' pairs of shoes is 
Find the derivative of the function to find out the critical points

Thus, for 4 pair of shoes profit is maximize.
Y=ax+b
a... slope
b... interception on the line y
you get the equation y=-1/2 *x + 12
Answer:
X= -3
Step-by-step explanation:
Subtract 7 from both sides of the equation
Simplify
Divide both sides of the equation by the same term
Simplify