如何在R Markdown中保留对齐乳胶方程式？

I'm having some difficulty left aligning equations in R Markdown (i.e. putting the equation on the far left side of page, and aligning subsequent lines). I've generally determined that I want to set the [fleqn] option in the amsmath package to left align all equations, but putting the following in my YAML header gives an error I'm having some difficulty left aligning equati