Which expression represents the fourth term in the binomial expansion of (e + 2f)10

Worth 100 points need the answers asap first row -x^2 2x^2 (x/2)^2 x^2 x is less than 2 x is greater than 2 x is less than or equal to 2 x is greater than or equal to 2 second row -5 -5/2 4 5 •2 is less than x& x is less than 4 •2 is less than or equal to x & x is less than or equal to 4 •2 is less than or equal to x& x is less than 4 •2 is less than x& x is less than or equal to 4

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me

Given δjkl : δxyz, find x. a)10 b)12 c)16 d)20