Extracting specific numbers from a vector

How can I extract a specific number from a vector, saving the new vector minus the extracted number as a new variable, and saving the counted extracted number as a new variable?

eg. Extracting '-20' from the following.

A = [2 4 6 5 6 5 4 3 -20 4 6 7 -20 3 4 5 6 1 -20];

A1 = [2 4 6 5 6 5 4 3 4 6 7 3 4 5 6 1];
A2 = 3

Answer 1

[Walter Roberson]

A1 = A(A ~= -20);
A2 = length(A) - length(A1);

Answer 2

[Azzi Abdelmalek]

idx=ismember(A,-20)
A1=A(~idx)
A2=sum(idx)