Three advanced abstract reasoning image tests

A close-up photo of a green chalkboard. The correct derivation steps of the quadratic formula are written in white chalk. First line: ax^2 + bx + c = 0. Second line: x^2 + (b/a)x = -c/a. Third line: completing the square. Final line: x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}. The handwriting is neat and clear. No garbled symbols.