Question 1124971
<br>
Written as a product of factors each raised to a power, a number is a perfect square (2nd power) only if all the exponents are multiples of 2 -- i.e., even.<br>
The "x" factor and the "3" factor both have even exponents; the "2" and "5" do not.<br>
So to make a perfect square, the expression needs another factor of 2 and another factor of 5 -- which means k is 5*2 = 10.