Allan is deriving the quadratic formula, as pictured below. His work is incorrect. In which step did Allan first make an error? Step 3, 4, 5 or 6?

What is the greatest common factor of 6a, 8a^{2}, and 14?

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

In a young single person's monthly budget, $150 is spent on food, $175 is spent on housing, and $175 is spend on other items. suppose you drew a circle graph to represent this information, what percent of the graph represents housing?