Question 24
Let ABC be an equilateral triangle, and D,E,F the midpoints of its sides. How many nondegenerate, pairwise noncongruent triangles can be obtained by choosing 3 of A,B,C,D,E,F?
How many ordered pairs (x,y) of integers satisfy $y^4-8y^2+7=8x^2-2x^2y^2-x^4$?
How many ordered pairs (x,y) of integers satisfy $y^4-8y^2+7=8x^2-2x^2y^2-x^4$?