Help please? I need to solve by factoring.

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1 Answer
Nov 30, 2017

Sure I'll help.

Explanation:

In order to factor the equation, we have to arrange the equation so it is all multiplication (essentially).

#2x^4 + 12x^3 + 16x^2 = 0#

First let's factor out the #2x^2#.

#2x^2(x^2+6x+8)=0#

Now, we are left with a simple trinomial in the brackets. Factor it normally.

#2x^2(x^2 + 4x+2x+8)=0#

#2x^2(x[x+4]+2[x+4])=0#

#2x^2(x+2)(x+4)=0#

Now that we have fully factored the equation, we can use this to find the solutions.

The solutions are points on the graph when #y=0#. To get this, #x# needs to equal to something that makes the entire equation #0#.

Let's start with #2x#. To get #0#, anything multiplied by #0# equals #0#. Therefore, #x=0#. That's one solution.

Next is #x+2#. Well, to get #0# here, #x# has to be #-2#, becasue #-2+2=0#. That's the second solution.

Finally, #x+4#. The same thing as before also applies here, except #x=-4#.

Therefore, the solutions to the function are #x=0, -2, -4#.

We can double check this by graphing the the function.

graph{2x^4 + 12x^3 + 16x^2 [-22.8, 22.82, -11.4, 11.4]}

Hope this helps :)