Can somebody answers this you , just a, b, and c .

a) ( -8 ) - 13 - ( -4 )

b) 4 - ( -7 ) + ( -2 )

c)( -7 )+ 3 - 20

i would really appreciate answers you .

What are the domain and range of f(x)=[1/5]x

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

What is the result of adding the system of equations? 2x+y=4 3x-y=6