Answer: 


y=9x+20
Step-by-step explanation:
5x-12y-17=0 (plus 17 from both sides)
5x-12y=17 (plus 12y from both sides)
5x=12y+17 (divide 5 from everything)

5x-12y-17=0 (plus 17 from both sides)
5x-12y=17 (minus 5x from both sides)
-12y=-5x+17 (divide everything by -12)

1*9(x+2)-(y+1)+3=0 (distribute 9 to x and to 2) (distribute -1 to y and to 1)
1*9x+18-y-1+3=0 (times 9x by 1)
9x+18-y-1+3=0 (combine like terms)
9x-y+20=0 (minus 20 from both sides)
9x-y=-20 (plus y to both sides)
9x=y-20 (divide 9 from both sides)

1*9(x+2)-(y+1)+3=0 (distribute 9 to x and to 2) (distribute -1 to y and to 1)
1*9x+18-y-1+3=0 (times 9x by 1)
9x+18-y-1+3=0 (combine like terms)
9x-y+20=0 (minus 20 from both sides)
9x-y=-20 (minus 9x from both sides)
-y=-9x-20 (divide -1 from everything)
y=9x+20