SOLUTION: The sum of an integer and three times another integer is 18. Determine the value of the two integers if their product is a maximum. Thanks! What I have so far: x + 3y = 18 x

Question 312323: The sum of an integer and three times another integer is 18. Determine the value of the two integers if their product is a maximum. Thanks!
What I have so far:
x + 3y = 18
x = 18 - 3y
Product = xy = y (18-3y)
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
The sum of an integer and three times another integer is 18. Determine the value of the two integers if their product is a maximum. Thanks!
What I have so far:
x + 3y = 18
x = 18 - 3y
Product = xy = y (18-3y)
Write it as a quadratic equation
f(y) = -3y^2 + 18y
Find the axis of symmetry using y = -b/(2a), where a=-3, b=18
y =
y =
y = +3
:
Find x
x = 18-3(3)
x = 9
RELATED QUESTIONS
An integer is 3 more than another. If the product of the two integers is equal to 2 more... (answered by ankor@dixie-net.com)

Find two integers that one integer is three times another, and the sum of their... (answered by Alan3354)

One integer is 2 times another. If the product of the two integers is... (answered by Boreal,addingup)

a positive integer is three times another positive integer. the sum of their reciprocals... (answered by MathTherapy)

1. One integer is 2 more than another. Their product is 35. Find the Integers 2. One... (answered by TimothyLamb)

The sum of two consecutive integers 111. Three times the larger integer less two times... (answered by checkley77)

An integer P is two thirds of another and their difference is ten.Find the two... (answered by checkley79)

If the ratio of two positive integers is 3 to 2,which of the following statements about... (answered by Alan3354)

One integer is 2 times another. If the product of the two integers is 98, then... (answered by MathLover1)