+900 Let $x$ and $y$ be nonnegative real numbers. If $x + y = 25$, then find the minimum value of $6x + 3y.$
+20 we get 3x+3y=75. since we need to add 3x, we just make x=0, since the questions says "nonnegative". therefore, the minimum value is 75.
+34 If we multiply both sides by 3, we get \(3x + 3y = 75\) . We notice that \(6x+3y\) is \(3x\) more than \(3x + 3y\). If \(x\) is 0, then \(3x\) is 0. 75 + 0 = 75, so the minumum value of \(6x + 3y\) is 75.
