Given x2 - 10x = 20. If completing the square was used to solve this equation, how much should be added to both sides of the equation?
2007-11-29 10:00:28 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
to get the no to be added:
easy 2 steps:
1. Divide th constant of 10x by 2
10/2 = 5
2. Then square the answer
5 square = 25!!!
Now to get the answer...
x2-10x+25=20+25
x2-10x+25=45
(x-5)2 = 45
x-5 = square root of 45
ans:5 plus and minus square root of 45
2007-11-29 16:04:04 · answer #1 · answered by camz54 2 · 0⤊ 0⤋
half the x term squared
x^2 - 10x+25 = 20+25
2007-11-29 10:03:58 · answer #2 · answered by RickSus R 5 · 0⤊ 0⤋
x+2 -10x + ____ = 20 + _____
1/2(-10) = (-5)^2
x^2 -10x + 25 = 20 + 25
(x-5)^2 = 45
2007-11-29 10:04:31 · answer #3 · answered by sayamiam 6 · 0⤊ 0⤋
to complete the square, add (b/2a)^2. The square will be (sqrt(a)x+b/2a)^2
x^2-10+25=20+25
(x-5)^2=55
x-5=+-sqrt(45)
x=5+-sqrt(45)
x=5+-3sqrt(5)
2007-11-29 10:06:19 · answer #4 · answered by someone2841 3 · 0⤊ 0⤋
You would add 25 to each side.
2007-11-29 10:05:47 · answer #5 · answered by lil bittt:] 2 · 0⤊ 0⤋
x=(-5/2)
2007-11-29 10:03:32 · answer #6 · answered by Brendan R 2 · 0⤊ 3⤋