Find the term that must be added to both sides of the equation so that the equation can be solved by the method of completing the square: x^2 +4x= 1. Then solve the equation by completing the square.
2007-01-15 19:26:18 · 4 answers · asked by Rubyx 2 in Science & Mathematics ➔ Mathematics
x^2 + 4x + 4 = 1 + 4
(x + 2)^2 = 5
x + 2 = +-sqrt(5)
x = -2 +-sqrt(5)
2007-01-15 19:36:45 · answer #1 · answered by ? 6 · 0⤊ 0⤋
x^2+4x = (x+2)^2-4 so x^2 +4x +4 =5
(x+2)^2 = 5 ==> x+2 = (+-sqrt 5)==> x= -2-+(sqrt5)
2007-01-16 08:25:34 · answer #2 · answered by santmann2002 7 · 0⤊ 0⤋
remember to complete teh square you must take the middle term. divide it by 2 and square it. so 4/2 =2 * 2 =4. so you would add 4.
s o you get (x+2)^2 = 5. take square root.
x+2 = +/- rad5
x= -2 +/- rad5
2007-01-16 03:38:20 · answer #3 · answered by Anonymous · 0⤊ 0⤋
x^2+4x=1
=>(x)^2+2.x.2+(2)^2=1+(2)^2 [adding (2)^2 or 4 to both sides
=>(x+2)*2=5
=>x+2=(sqrt)+/-5
=>x=(sqrt)+- 5-2
2007-01-16 04:52:13 · answer #4 · answered by alpha 7 · 0⤊ 0⤋