Plz help wit 1 3 4 i

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

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°