15 points due soon there are two parts the first pic is part 1 second pic is part 2

Use the multiplier method to incrases £258 by 43%

Given: x + y = 6. if xe (-15, -6, -1), then which of the following sets of ordered pairs are solutions? © {(-15, -21), (-6, -12), (-1, -7)} [(-15, 21), (-6, , 7)} {(-15, 21), (-6, 12), (-1, -7)}

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie