Question

I really don't understand this could someone explain?

Answer 1

`\bf \begin{array}{lllll} 1.3t^3&+0.4t^2&-24t\\\\ 0t^3&-0.6t^2&+18t&-8\\\\ --&--&--&--\\ 1.3t^3&-0.2t^2&-6t&-8\\ A&B&C&D \end{array}`

if you were to align those two polynomials vertically, you'd align the like-terms, below each other like so, if that helps