+78 Find all values of x such that \(\sqrt{4x^2} - \sqrt{x^2} = 6\)
Please help me asap! I appreciate your help!
CPhill said that it is:
sqrt (4x^2) - sqrt (x^2) = 6 we can write
2sqrt (x^2) - sqrt (x^2) = 6
sqrt (x^2) = 6 square both sides
x^2 = 36 take both roots
x = ± 6
When i put in the answer, the website said that 6 is incorrect. Can anybody clarify/ tell me the new answer?
+37159 A little different approach might work:
sqrt (4x^2) = +- 2x
sqrt(x^2) = +- x
so it could be
-2x-x = 6 x= -2
-2x+x = 6 x = -6
2x-x = 6 x= 6
2x+x = 6 x = 2 2 and -2 won't work, but 6 and -6 should work
