<p>How do I do this problem?</p>
<p>If x and y are pos. integers and the GCF of x^2y^2 and xy^3 is 45, then what could y equal?</p>
<p>Choices:</p>
<p>A - 45
B - 15
C - 9
D - 5
E - 3</p>
<p>Answer is E, 3</p>
<p>I have to prove my user id. lol</p>
<p>x^2y^2 = y^2 x^2
xy^3 = y^2 xy
since y^2 is a common factor of both monomials,
y^2 has to be a "part" (factor) of 45
45 = (3^2) (5)
y = 3</p>