Question 705115: Please can someone help me with this question!! thanks
If x<0 and y >O Determine the sign.
1.a)xy^2 divided by y
b) 1-x^2 divided by 1-y
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! 1a)
x < 0, so x is negative
y > 0, so y is positive
This means y^2 is positive and so is y^2 divided by y
Multiply this positive number (y^2 divided by y) with a negative number (x) to get
xy^2 over y
and this result will be negative since negative times positive = negative.
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1b)
x^2 is always positive regardless if x is positive or negative
1 - x^2 is positive only if x^2 < 1 or if -1 < x < 1
1 - y is positive only if y < 1
Since x < 0, we know for a fact that 1 - x^2 is negative (see the rule above)
Because y > 0, we know that 1-y is negative (again, look at the rule)
So 1-x^2 is negative when x < 0 and 1-y is negative when y > 0
Therefore 1-x^2 divided by 1-y is positive (negative/negative = positive)
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