Respuesta :

y=mx+b
m=slope
b=y intercept
wer are given the point (4,9), therefor one solution is x=4, y=9 so subsitute ad solve for b
9=6(4)+b
9=24+b
subtract 24
-15=b

therefor
y=4x-15
subtract 4x from both sides
-4x+1y=-15 or
4x-y=15