using quadratic equation by completing the square?

1 ⤊

using quadratic equation by completing the square?

4 = x^2 + 10x

2007-03-12 01:47:30 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

2 answers

4 = x² + 10x

Take half the value of the x coefficient (10/2 = 5) and square it (5² = 25) and add to both sides

29 = x² + 10x + 25

Factor

29 = (x + 5)²

Square root both sides, remembering the square root can be positive or negative

±√29 = x + 5

x = ±√29 - 5

2007-03-12 01:53:34 · answer #1 · answered by Tom :: Athier than Thou 6 · 1⤊ 0⤋

x^2+10x-4=0

Quadratic: A=1 B=10 C= -4

(-10 +- sqrt(100 + 16))/2

x= -5+-2*sqrt 29

2007-03-12 08:56:56 · answer #2 · answered by blighmaster 3 · 0⤊ 0⤋