20. Calcule o valor numérico das expressões: a) x – y (para x =5 e y = -4) b) 3x + a (para x =2 e a=6) c) 2x + m ( para x = -1 e m = -3) d) m – 2 a ( para m =3 e a = -5) e) x + y ( para x = ½ e y = -1/5) f) a –b ( para a =3 e b = -1/2)

Gail is making costumes for a school play. each rabbit costume needs one and one half yards of white fur fabric, a yard of blue striped fabric, and a quarter of a yard of pink felt for the ears. g? ail needs to make eight rabbit man yards will she need, for the white fur fabric, blue striped fabric, and pink felt?