Question 80634This question is from textbook
: I'm having trouble solving this word problem. The product of 2 positive integers is 30. Find the integers if the larger is 4 less than twice the smaller. We need to represent the variable(s), write the equation, and solve the equation. I believe the 2 positive integers are 5 and 6, but i don't know how to write the equation to be able to solve it. Thank you,
Jennie
This question is from textbook
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! :
Just write an equation for what it says:
:
"The product of 2 positive integers is 30."
x * y = 30
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"Find the integers if the larger is 4 less than twice the smaller."
Let x be the larger:
x = 2y - 4
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Substitute (2y-x) for x in the 1st equation:
(2y-4) * y = 30
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2y^2 - 4y = 30
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2y^2 - 4y - 30 = 0; now a quadratic equation
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y^2 - 2y - 15 = 0; simplified, divided eq by 2
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(y - 5)(y + 3) = 0; easily factored
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y = +5; it said the positive integer
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Using the 1st equation find x;
5x = 30
x = 30/5
x = 6, just like you said
:
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Check it in the 2nd equation:
6 = 2(5) - 4
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