you first plug (substitute) in y
-3x - 3(-5x-17)=3
then distribute
-3x+15x+51=3
now combine like terms
12x+51=3
subtract to get 12x by itself
12x=3-51 or 12x=-48
lastly divide by 12 to find x
12x/12=-48/12
x=-4
now find y by plugging x into the other equation
y=-5(-4)-17
y=3
(-4,3)
