Can you help me with this quadratic world problem?

Question

An integer is five times more than another integer. Three times the larger integer is 11 more than the square of the smaller integer. Find the two integers. Explain how you found your answer.

Answer 1

Hi Sun,

 

Let's translate the English into math. . .

 

Let the small integer = X

 

The larger integer is five times more --> 5X

 

Three times the larger integer is 11 more than the square of the smaller--> 15X = X^2 + 11

 

Now we'll subtract 15X from both sides --> X^2 - 15X + 11 = 0

 

For the quadratic equation, a = 1    b = -15    c = 11

 

X = (15 +/- sq root (225-44)) / 2

 

X = (15 +/- 13.45) / 2

 

X = 28.45/2       X = 1.55/2

 

X = 14.23         X = 0.78

 

These are not integers so the question is faulty.

 

Dan