Question 1118094
<br>
4x^6 is a perfect square: (2x^3)^2 = 4x^6.<br>
When you factor 4x^6 out of the original expression 20x^7, what is left is 5x: {{{(20x^7)/(4x^6) = 5x}}}.<br>
Neither 5 nor x is a perfect square, so 4x^6 is the largest perfect square factor of 20x^7.