30 points really hard mulitiquestions

When a formula is solved for a particular variable, several different equivalent forms may be possible. if we solved a=1/2bh for h, one possible correct answer is h=2a/b . which one of the following is not equivalent to this? a. h= 2(a/b) b. h= 2a(1/b) c. h= a/1/2b d. h= 1/2a/b

Thelime contains the point(-3,0) and parallel x-3y=3( show all work)

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