Life quiz STEM

Elementary Math Quiz

If (x+x+x) = x*x*x  and x <>0 (x is not zero) then what’s the value of x?

I like this one a lot because x=0 would be an obvious answer and it’s taken away, and then when you plot it, you get 2 correct answers. Let’s see how it’s done…

(x+x+x) = x*x*x

so, 3x=x^3

or  3 = x^2  (after diving by x)

therefore x = sqrt(3)

x=3

Nice! But we also know that negative number * negative number also makes the output positive. So, let’s plot the equations…

Aha, there seems to be 2 possibilities: one on the left side (negative) and one on the right side (positive). So, the correct answers are:

x=3

and x=3

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