Math Test: a x 2 + b x + c = 0 {\displaystyle ax^2 + bx + c = 0\,\!} ∫ a x ∫ a s f ( y ) d y d s = ∫ a x f ( y ) ( x − y ) d y {\displaystyle \int_a^x \!\!\!\int_a^s f(y)\,dy\,ds = \int_a^x f(y)(x-y)\,dy}
