jehadhajr jehadhajr
  • 03-05-2017
  • Mathematics
contestada

what number must you add to complete the square x^2+4x=15

Respuesta :

Sxerks Sxerks
  • 03-05-2017
Since we want it in the form: (x - a)², let's first expand (x - a)² and then equate for the coefficients.

(x - a)² = x² - 2ax + a²
x² + 4x - 15 = x² - 2ax + a²

Now, let's focus on the middle term.
4x = -2ax
4 = -2a
a = -2

Thus, we know that a = -2
Then, we can say (x + 2)² = x² + 4x - 15
x² + 4x + 4 = x² + 4x - 15
Thus, 19 units are needed in order to complete the square to produce:
(x + 2)²
Answer Link

Otras preguntas

What is the empirical formula for a sample containing 81.70% carbon and 18.29% hydrogen?
Narrative form can be used in documentary films.
Individuals with dissociative disorders have ____
How many ml of 0.250 m h2so4 is required to completely react with 25.0 ml of 1.50 m naoh?
Because obesity apparently has many causes even in a single individual the best approach seems to be
Early christian music was most strongly influenced by:
What should you do if you fall overboard into cold water?
I don't get this problem
What writing style should you use in filling out a short-answer section on a job or college application?
The length of a rectangle is two-fifths of its perimeter. if the width of the rectangle is 35 inches, what is its length in inches?