SOLUTION: Please help me solve this problem: Find k to make the trinomial a perfect square: r square + 10r + k Thank you, Carrie

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Please help me solve this problem: Find k to make the trinomial a perfect square: r square + 10r + k Thank you, Carrie      Log On


   

Question 236844: Please help me solve this problem:
Find k to make the trinomial a perfect square:
r square + 10r + k
Thank you, Carrie
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
when you "complete the square", the constant term is the square of one half of the coefficient of the 1st order term

yeah, it sounds complicated; but it isn't

in this case; k must be half of 10, squared

r^2 + 10r + 25 = (r + 5)^2