Answer:
(9,126)
Step-by-step explanation:
Make sure x and y are on the same side

Eliminate y by multiplying the first equation by 4 then adding both equations together

Plug the x value (9) into one of the equations

Solve

x=9, y=126
(9,126)
Margaret traveled 80 miles to the appointment.
Step-by-step explanation:
Given,
Speed while driving for appointment = 80 mph
Speed while coming back = 70 mph
Let,
x be the time taken for the trip
y be the distance covered
Distance = Speed*Time
y = 80x Eqn 1
Time taken in return trip = x+1/7
y = 70(x+1/7)
Eqn 2
Putting value of y from Eqn 1 in Eqn 2

Dividing both sides by 10

x = 1 hour
Putting x = 1 in Eqn 1

Margaret traveled 80 miles to the appointment.
Keywords: linear equation, substitution method
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Answer:
A - 90 units
B = 0 units
Step-by-step explanation:
Here we have two models A and B with the following particulars
Model A B (in minutes)
Assembly 20 15
Packing 10 12
Objective function to maxmize is the total profit
where A and B denote the number of units produced by corresponding models.
Constraints are

These equations would have solutions as positive only
Intersection of these would be at the point
i) (A,B) = (60,40)
Or if one model is made 0 then the points would be
ii) (A,B) = (90,0) oriii) (0, 90)
Let us calculate Z for these three points
A B Profit
60 40 1040
90 0 1080
0 90 720
So we find that optimum solution is
A -90 units and B = 0 units.