find all real solutions

Hello, yasaminG!

I assume that it's supposed to be an <u>equation</u>.

how do i do this?     x2(x27)+12\displaystyle \;\;x^2(x^2\,-\,7)\,+\,12
We have:   x47x2+12  =  0\displaystyle \;x^4\,-\,7x^2\,+12\;=\;0

Factor:   (x24)(x23)  =  0\displaystyle \;(x^2\,-\,4)(x^2\,-\,3)\;=\;0

Then:   x24=0        x2=4        x=±2\displaystyle \;x^2\,-4\:=\:0\;\;\Rightarrow\;\;x^2\,=\,4\;\;\Rightarrow\;\;x\,=\,\pm2

And:   x23=0        x2=3        x=±3\displaystyle \;x^2\,-\,3\:=\:0\;\;\Rightarrow\;\;x^2\,=\,3\;\;\Rightarrow\;\;x\,=\,\pm\sqrt{3}
 
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