How do I solve this system of equations by adding, subtracting, or multiplying?
x-y=8;x+y=12

It takes a total of 6 hours to fill up an inground backyard pool using a standard house. a function can represent this situation to represent the amount of water in the pool until it is full a function of time the hose is running. determine the domain for the function

Evaluate the expression for the given value of the variable 7a - 4a for a =8

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