PLEASE HELP WITH ALGEBRA
Evaluate P(x, y)=x^2 + xy + y^2

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

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

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.