How do you solve the following linear system: #-7x - 5y =4, -x + y = 21 #?
1 Answer
Nov 14, 2015
Explanation:
We start with:
There are three ways of solving these problems. I'll choose substitution, as I find it easier. Let's start. First of all, we leave
We now substitute this into the other equation:
We now substitute this into any of the equation. I'll choose the second one: