if you are doing standard form which is in algebra 1 which is Ax+By=C you would start off with either one you like i like to start off with the X term so you would just take out the -11y and your first problem would be z=5x then you subtract the 5 on both sides which will get you and for the left side you would get -5x+z=-11y then you add the -11y to its self and to z i believe but that’s all i can remember sorry if it’s wrong