PLEASE HELP. SAT.
If a is equal to the sum of band c, what is the difference of band c?

In terms of b and a
In terms of c and a

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem

What does independent variable and dependent variable mean in math?