Originally Posted by

**durrrr** 1st equation: x + y = 5 and 2nd equation: x^2/16 + y^2/9 = 1

y = x - 5

Sub into 2nd equation...

x^2/16 + (x-5)^2/9 = 1

9x^2/144 + ???/144 = 1

Sorry, I'm obviously not very good at math. I don't know what to do to the (x - 5). I'd really appreciate if somebody could finish the equation in baby steps. I understand the concept behind tangents and the actual question, there are obviously just gaping holes in my basic math knowledge when it comes to completing the solution.