Question

http://prntscr.com/9nsbe2

Answer 1

@caozeyuan

Answer 2

You know there are serveral ways to solve problems such as this. For example if you cant remeber how to do it their are online calculatorrs that solve these kind of problems all day!
Would you like a such site? for reference?

Answer 3

it works best with substitution, so try it

Answer 4

sure ig

Answer 5

Here ;) : https://mathway.com/

Answer 6

how does it work? I'm confused.

Answer 7

so if x=a+b and x+y=a+c, what is y?

Answer 8

idk