1)
x^2 = 2x
x^2 - 2x = 0
x(x-2)=0
x=0 or x=2
Not Suff
2)
x^3 = 3x
x^3 - 3x = 0
x(x + sqrt3)(x - sqrt3) = 0
x=0 or x=-sqrt3 or x=sqrt3
Not suff
Together the only common result is 0 so 1 and 2 together are SUFF
GMATfocus question
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Source: Beat The GMAT — Data Sufficiency |
thanks dmateer...just to elaborate on this question, the OA explanation contains a typo for (2) it says:
(2) if x^3 = 3x, then x^3 - 3x = 0. This can be solved by factoring this equation x^2(x-3) = 0. ...so x^2 = 0 and x-3 = 0 giving 0 and 3 as the answer....
Either way you get the same answer (0 is the only commong factor btw the two), but you would think the money GMAC makes you fork over for GMATfocus they would at least not have any typos. Thanks
(2) if x^3 = 3x, then x^3 - 3x = 0. This can be solved by factoring this equation x^2(x-3) = 0. ...so x^2 = 0 and x-3 = 0 giving 0 and 3 as the answer....
Either way you get the same answer (0 is the only commong factor btw the two), but you would think the money GMAC makes you fork over for GMATfocus they would at least not have any typos. Thanks
