Steps: 1. Change x + y= 27 into y=mx+ b form 2. Subtract x on both sides Y= -x + 27 3. Substitute the y in x + 3y= 73 for -x + 27
X + 3(-x + 27) = 73 X + -3x + 81= 73 -2x + 81= 73 4. Now subtract 81 on both sides -2x=-8 5. X= 4 6. Now solve for y 7. Now substitute the x in x + y= 27 for 4 8. 4 + y= 27 9. Subtract 4 on both sides 10. Y= 23 11. Your answer is: x= -4 and y= 23 or (-4,23)