What is the greatest common factor of 18 54 and 72?

Kylie explained that (-4x+9)^2 will result in a difference of squares because (-4x+9)^2 (-4x+9)^2 =(-4x)^2+(9)^2=16x^2+81

Which of the symbols correctly relates the two numbers below check all that apply 6? 6

Identify the number as a regional or irrational.explain. 291.87