solve the equation: √x+6+√2-x=4
\[\sqrt{x+6}+\sqrt{2-x}=4?\]
yeah, that's my question
\[\sqrt{x+6}=4-\sqrt{2-x}\]
i don't know how to type it just like that in the posts..
first thing i did was subracted sqrt(2-x) on both sides
now i'm going to square both sides
remember \[(a+b)^2=a^2+2ab+b^2\] \[(\sqrt{x+6})^2=(4-\sqrt{2-x})^2\] \[x+6=15-2(4)(\sqrt{2-x})+(\sqrt{2-x})^2\]
oops 4^2 is 16
type-o
\[x+6=16-2(4)\sqrt{2-x}+(\sqrt{2-x})^2\]
\[x+6=16-8\sqrt{2-x}+(2-x)\]
now we simplify and put sqrt{2-x} by itself on one side \[x+6=18-x-8\sqrt{2-x}\] \[x+x+6-18=-8\sqrt{2-x}\]
\[2x-12=-8\sqrt{2-x}\] we can leave the -8 there in front of the sqrt{2-x} now square both sides \[(2x-12)^2=(-8\sqrt{2-x})^2\]
lol
\[4x^2-2(2)(12)x+144=64(2-x)\] \[4x^2-48x+144=128-64x\] see we don't have any square root thingy ma jiggers to worry about now
now we put everything on one side and see if we can factor or we can use the quadratic formula
\[4x^2-48x+64x+144-128=0\]
\[4x^2+16x+ 16=0\]
now each term has the factor 4 in common we can factor 4 out and then divide both sides by 4 \[x^2+4x+4=0\]
this can easily be factored (x+2)^2=0
x+2=0 x=-2
that seemed like a lot of work and you just whipped it out like nothing. THANK you, first person where they actually care about helping and explaining
i don't see the point in just giving an answer without an explanation
i very much appreciate that!! you have NO idea
np
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