Evaluate when a=15:2(a-5)+2

When you answer this can you explain

The reflexive property of congruence lets you say that ∠pqr ≅

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?