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Solve by using the most apropiate method. Give irrational roots in simplest form. (x+3)^2 + 6(x+3)=16?

2007-05-29 15:11:27 · 7 answers · asked by Starlight 1 in Science & Mathematics Mathematics

7 answers

you will square the (x+3) first and get

x^2 + 6x +9 + 6x+18 = 16 add up like terms

x^2 +12x + 27 =16 subtract the 16 on both sides

x^2 +12x + 11 = 0

factor by looking for 2 numbers that multiply to give 11 and add up to give 12 and it will be ( 1 and 11)

so you will have

(x+1)(x+11)=0 solve for x and you will end up with

x= -1 or x = -11

2007-05-29 15:17:00 · answer #1 · answered by justplainme64 3 · 0 4

There is no need to square the binomials in this situation. Treat each (x + 3) as a single variable and factor normally:

(x+3)^2 + 6(x+3) = 16

(x+3)^2 + 6(x+3) - 16 = 0

[(x + 3) + 8] [(x + 3) - 2] = 0

(x + 3) + 8 = 0
x + 11 = 0
x = -11

(x + 3) - 2 = 0
x + 1 = 0
x = -1

There are no irrational roots in this situation, both roots (-11 and -1) are rational.

2007-05-29 22:19:13 · answer #2 · answered by suesysgoddess 6 · 1 2

Let y = x + 3
y² + 6y - 16 = 0
(y + 8).(y - 2) = 0
y = - 8, y = 2
x + 3 = - 8, x + 3 = 2
x = - 11, x = - 1

2007-05-30 02:36:35 · answer #3 · answered by Como 7 · 1 2

x^2 + 6x + 9 + 6x + 18 - 16 = 0
x^2 + 12x +11 = 0
(x + 11)(x + 1) = 0
x = -11 or x = -1

2007-05-29 22:16:39 · answer #4 · answered by TychaBrahe 7 · 0 5

6x + 18 + x^2 + 6 = 16

x^2 + 6x + 22 = 16

x^2 + 6x = -6

x^2 + 6x + 9 = 3

(x + 3)^2 = 3

x+3 = + and - radical 3

x = -3 + and - radical 3

2007-05-29 22:20:52 · answer #5 · answered by Anonymous · 0 3

(4+3)^2+6(6+3)=ya mamma

2007-05-29 22:19:00 · answer #6 · answered by comethunter 3 · 0 3

-1

2007-05-29 22:17:23 · answer #7 · answered by Mark S 1 · 0 4

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