Which expression is equivalent to 1/3b - 7?

-1/3(b+21) 1/3 (b-21) -1/3 (b-21) 1/3(b+21)

There are 12 boy and13 girls in a class. if the teacher randomly chooses a student’s name out of a hat what is the probability it will be a girl

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

Which equation represents the model shown? a)1/3 divide 1/6 = 2 b)2/3 divide 1/6 = 2/18 c)1/3 divide 1/6 = 1/18 d)2/3 divide 1/6 =4