198k views
2 votes
Find a solution for 5x+4y=-30 and 3x-9y=-18

User Mogio
by
4.3k points

1 Answer

6 votes

{5x + 4y = -30

{3x - 9y = -18 | : 3

{5x + 4y = -30

{x - 3y = -6 | + 3y

{5x + 4y = -30

{x = 3y - 6

{5(3y - 6) + 4y = -30

{x = 3y - 6

{15y - 30 + 4y = -30 | + 30

{x = 3y - 6

{19y = 0 | : 19

{x = 3y - 6

{y = 0

{x = 3 · 0 - 6

{y = 0

{x = -6

User LoneRanger
by
5.5k points