# Magic formula

Was grading some student work and noticed that when they are supposed to solve for
$\left(\frac{5y}{4}-\frac{1}{2}\right)^2 +\frac{1}{16} = 1$,
10 out of 16 students expanded the above into a quadratic equation and then used the quadratic formula to get a solution. Of course, along the way, a couple of them made some mistakes in the algebra and got the wrong answer.

This entry was posted in Algebra, Teaching. Bookmark the permalink.

### 2 Responses to Magic formula

1. John Cook says: