The square roots are a cinch, but the complication they introduce is that square roots are "plus or minus"
You have (+2x) – (+x) = 8 which is the same as +2x +x = 8 So you have four possibilities, namely:
+2x + x = 8 so +3x = 8 and x = +8/3
+2x – x = 8 so +x = 8 and x = +8
–2x + x = 8 so –x = 8 and x = –8
–2x – x = 8 so –3x = 8 and x = –8/3
"all values" are +8 and –8 and +8/3 and –8/3
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