can someone help me figure this out step by step?: $$x ^{2}+(9\sqrt{3})^{2}=4x ^{2}$$

Question

can someone help me figure this out step by step?:       $$x ^{2}+(9\sqrt{3})^{2}=4x ^{2}$$

allank · Answer

First share out the exponent to each of the terms in the parentheses..9^2*(sqrt3)^2

allank · Answer

To get 81*3 = 243. ok with that step?

allank · Answer

still there @pllfan ?

anonymous · Answer

yup

allank · Answer

okay with the first step?

anonymous · Answer

done

allank · Answer

Nice. so now it's 243 = 3x^2  Right?

anonymous · Answer

yes

allank · Answer

Wonderful. can u finish off from here?

anonymous · Answer

um what happens after you divide 243 by 3

allank · Answer

To get the value of x, you now get the sqrt of both sides of the equation. can u do that?

anonymous · Answer

yes thank you

allank · Answer

you're welcome. and do remember that your answer will be  plusORminus (certain value).

anonymous · Answer

is it both?

allank · Answer

Just a sec. Sorry, no. take the positive value. The rules are,
sqrt of a known number = positive value e.g. sqrt(4) = 2
sqrt of an unknown number = positive/negative e.g. sqrt(x^2) = +x and -x
Hope that helps.

anonymous · Answer

wait in what situatuon could you use the plus-minus sign?