SOLUTION: A student is asked to solve the equation x^2 +x - 6 = 5 The student gives the following steps: (x - 2)(x + 3) = 5 (x - 2) = 5 (x + 3) = 5 x = 7 x = 2 Expla

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A student is asked to solve the equation x^2 +x - 6 = 5 The student gives the following steps: (x - 2)(x + 3) = 5 (x - 2) = 5 (x + 3) = 5 x = 7 x = 2 Expla      Log On


   



Question 167450: A student is asked to solve the equation

x^2 +x - 6 = 5
The student gives the following steps:
(x - 2)(x + 3) = 5
(x - 2) = 5 (x + 3) = 5
x = 7 x = 2
Explain whether or not this is correct, and make any necessary corrections.




Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
The approach is WRONG.
Proof:
7^2+7-6=5
49+7-6=5
50=5 is an invalid proof.
2^2+2-6=5
4+2-6=5
0=5 is another invalid proof.
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The proper solution follows:
x^2+x-6=5
x^2+x-6-5=0
x^2+x-11=0
x=%28-b%2B-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29
x=(-1+-sqrt[1^2-4*1*-11)/2*1
x=(-1+-sqrt[1+44])/2
x=(-1+-sqrt45)/2
x=(-1+-6.7082)/2
x=(-1+6.7082)/2
x=5.7082/2
x=2.8541 answer.
x=(-1-6.7082)/2
x=-7.7082/2
x=-3.8541 answer.