How do I write a two-column proof to verify each statement

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Find the least common denominator for thesetvo rational expressions.n^2/n^2+4n+4 -3/n^2+7n+10

]supplementary angles are two angles that add up to . • complementary angles are two angles that add up to degrees. • adjacent angles share a and a • congruent angles have the measure. • an triangle has one angle that is greater than 90 degrees. • a triangle with angles 45°, 45°, and 90° would be a triangle