When doing this problem, I would recommend lining up all your variables. SO4A plus 7B equal 10/8, A plus 3C equaling -5 and 6B plus 3C equaling 15. Now we want to look for an equation that already has one of the variables missing. And when I look here, all three of them have a variable missing. So then we're going to look for variables that are easy to combine. So I'm going to get rid of the C's to start because the top equation didn't have AC in it at all. So we're going to look at combining equation two and three and getting rid of the C If I combine two and three to get rid of the CI, need to multiply 1 or the other by a negative. So let's do the number 2 by -1. So we get -8 A -3 C equal 5. We're going to leave #3 alone. So we get 6B plus 3C equaling 15. When we add that, we have -8 A plus 6B equaling 20. Now I like to keep my numbers as small as possible, and I realize all of those are divisible by two. So we're going to take that and make it -4 A plus 3B equaling 10. This is my new equation. Let's call it four. So now I'm going to combine 4 directly with one because one didn't have any CS in it. So if we combine one and four together, we can see 4A plus 7B equal 10 and -4 A plus 7B equal -4 A plus 3B equal 10. Equation 14A plus 7B equal 10, equation 4 Right here the -4 A plus 3B equal 10. I add those, the A's cancel, we get 10B equaling 20. So B equal 2. Once I get, BI can substitute it back into either one or four. If I use one, we have four a + 7 * 2 equaling 10, so 4A plus 14 equal 10 four A equal -4 A equal -1. And if I have A and BI can substitute it into any of the originals to find the C So let's say 8 * -1 + 3 C equal -5 negative 8 + 3 C equal -5. If I add the -8 to the other side, we get 3C. Equaling 3 or C is 1, so -1 two and one. So this is going to be consistent because there's a solution. They're also independent. Now remember, if we're hesitant at all whether we got it right, we can always check these answers in all three of the equations. So does 4 * -1 + 7 * 2 really equal 10? Well -4 + 14 does equal 10, so that's the first equation check. Does 8 * -1 + 3 * 1 equal -5 Negative 8 + 3 does equal -5 that's the second equation check and the last one 6 * 2 + 3 * 1. Does that equal 15 12 + 3 does equal 15? Hope this helps.