Using the numbers [6, -5, 1.5, 11], create an equation that equals 7.3. You can use basic arithmetic operations (+, -, *, /) and each number can only be used once. Show your work in <think> </think> tags. And return the final equation and answer in <answer> </answer> tags, for example <answer> 3 / 5 + 4 * 1 = 5 </answer>.