Jenny left her house at 8 a. m. and went to school at a speed of 2 2 3 mph. her brother jim left house 4 minutes later and went to the same school. what must his speed be if he wants to keep the same distance between his sister and himself?

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.