What is this place called

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?

Consider the input and output values for f(x) = 2x - 3 and g(x) = 2x + 7. what is a reasonable explanation for different rules with different input values producing the same sequence?

Use matrices to solve this linear system: 5x1 − 2x2 = −30 2x1 − x2 = −13 x1 = x2 =