given value to solve quadratic eqn: x=2,-2, x^2=x+6

[jshaziza]

Hey, I don't understand what they mean when they put x=2,-2, x^2=x+6.
With the other equations they would give me lets say x=5, x^2-4x-5=0
It tells me to determine if the given value is a solution of the given quadratic equation. Can someone please tell me what they mean in the first equation. Thx.

 

[Guest]

Take a look at that equation again. Can you make it a quadratic?

 

[Denis]

Re: given value to solve quadratic equation

Hey, I don't understand what they mean when they put x=2,-2, x^2=x+6.

They're telling you to rewrite the equation in quadratic format:
x^2 - x - 6 = 0
Then solve that equation for x; is your answer x=2 or x=-2 : yes or no?

If you don't understand that, see your teacher; can't teach here.

 

[Mrspi]

If they're asking if the given value is a solution for the equation, you could always substitute the value given for x, and see if the equation is true. If it IS, then the given value is a solution.

For example, you are given x = 5, and the equation x<SUP>2</SUP> -4x - 5 = 0. To determine whether 5 is a solution, substitute 5 for x:

(5)<SUP>2</SUP> - 4(5) - 5 = 0
25 - 20 - 5 = 0
0 = 0
Since this is true, we know that 5 is a solution of the given equation.