Which angles are supplementary to each other?

Which shows one way to determine the factors of  x3  +  5x2  –  6x  –  30 by grouping? x(x2  –  5)  +  6(x2  –  5)x(x2  +  5)  –  6(x2  +  5)x2(x  –  5)  +  6(x  –  5)x2(x  +  5)  –  6(x  +  5)

Polygons efgh and e′f′g′h′ are shown on the coordinate grid: what set of transformations is performed on efgh to form e′f′g′h′? a. a translation 1 unit to the left followed by a 90-degree counterclockwise rotation about the origin b. a translation 1 unit to the right followed by a 90-degree counterclockwise rotation about the origin c. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the right d. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the left

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem