It’s the first one, seven (7)
126 = 63 x 2 = 21 x 3 x 2 = 7 x 3 x 3 x 2
=> 126 = 2 x 3² x 7
I am a size 12 in women and I wear a size 26 in men but I still have a little room. You should try a size 22 maybe?
6x^5 - 11x^4 - 10x³ - 54x³ + 99x² + 90x
6x^5 - 11x^4 + (-10x³ - 54x³) + 99x² + 90x collect like terms
6x^5 - 11x^4 - 64x³ + 99x² + 90x simplify
hope this helps, God bless!