# Stunning Algebra: (December 7 – December 14, 2013)

Prime Roots

The x-intercepts of the equation y=x2-30x+k are prime numbers. What is/are the value(s) of K?

1. John Rey Jimenez. Negros Occidental High School

2. Arsh Singh. yourmathguru.com

3. Jomari Tan. DLSU

5. Vincenzo Roque. University of the Philippines – Diliman

6. John Warner.English teacher.VHS. Bielefeld,Germany

7. Ceasar Ian Pedro. University of the Philippines-Diliman

8. Oen Can. Saint Mary’s University

9. Marlon Chris Malicsi, UST

10. Muthu Krishnan.Kle college , Bengaluru

11. Sebastian Pineda Berrío. Colombia.

12. Muthu Krishnan , Kle College , Bengaluru

### Dan

Blogger and a Math enthusiast. Has no interest in Mathematics until MMC came. Aside from doing math, he also loves to travel and watch movies.

### 9 Responses

1. Possible values for k are 23*7= 161, 19*11= 209 and 17*13= 221.

2. Vincenzo Roque says:

K = 161, 209 or 221
(UPD)

3. John Warner says:

x^2 – 30x + k = y
at the x-intercepts y=0
30x – x^2 = k
x(30 – x) = k
x and (30 – x) are prime according to the problem
so x could be 7 gives (30-x)= 23 , 11 gives (30-x) = 19 , or 13 gives (30-x) = 17
=> k is either 7*23 = 161, 11*19 = 209 or 13*17 = 221

4. Caesar Pedro says:

k = {161, 209, 221}

5. John Warner says:

I am an English teacher at VHS Bielefeld in Germany.

6. Muthukrishnan , Kle college , bengaluru

values of k are 161,209,247

7. values of k are 161,209,221

8. kryptonj123 says:

The correct answer is 161,209,221, Please check the solution of Mr. Warner.

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