Algebra Pen - Good for Math test and exam

it's good for getting good mark. The idea of pattern is come from the top window of Melbourne Art Gallery. Algebra formula's below here: 1. (a + b)2 = a2 + 2ab + b2; a2 + b2 = (a + b)2 − 2ab 2. (a − b)2 = a2 − 2ab + b2; a2 + b2 = (a − b)2 + 2ab 3. (a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca) 4. (a + b)3 = a3 + b3 + 3ab(a + b); a3 + b3 = (a + b)3 − 3ab(a + b) 5. (a − b)3 = a3 − b3 − 3ab(a − b); a3 − b3 = (a − b)3 + 3ab(a − b) 6. a2 − b2 = (a + b)(a − b) 7. a3 − b3 = (a − b)(a2 + ab + b2) 8. a3 + b3 = (a + b)(a2 − ab + b2) 9. an − bn = (a − b)(an−1 + an−2b + an−3b2 + ··· + bn−1)