Let $a$ and $b$ be real numbers, where $a < b$, and let $A = (a,a^2)$ and $B = (b,b^2)$. The line $\overline{AB}$ (meaning the unique line that contains the point $A$ and the point $B$) has slope $2$. Find $a + b$.
Pretty easy
(b^2 - a^2) / ( b -a) = 2
(b + a) (b - a) / (b - a) = 2
b + a = 2
+1678 
