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# help

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If x is an element of the set {-1, 1, 2} and y is an element of the set {-2, -1, 0, 1, 2}, how many distinct values of x^y are positive?

Nov 20, 2019

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The only way to get the answer is to read the explanation ENTIRELY

List this out, trust me, it won't take long.

We see that there are 3 * 5 = 15 total possible values of x^y.

We find all the number of values that are NEGATIVE, then subtract that number from 15.

Looking at the y sets, we see that anything value of y that is -2, 0, 2, will create positive values no matter what.

So the y values can be -1 or 1.

There is only one x-value that has potential to be negative, and that is -1.

We see that -1-1 and -1both create negative values.

Since there are negative values.

15 - 2 = THE ANSWER?

We check with a table

 x values y values xy -1 -2 1 1 -1 1 2 0 1 -1 1 -1 1 2 1 2 -2 1/4 -1 -1 -1 1 0 1 2 1 2 -1 2 1 1 -2 1 2 -1 1/2 -1 0 1 1 1 1 2 2 4

BUT WAIT! They said distinct.

So count the distinct values in the table, and you should get the answer.

Nov 20, 2019
edited by CalculatorUser  Nov 20, 2019