The point-slope equation:
y - y1 = m(x - x1)
for a line that passes through point (x1, y1) and has slope m.
Use x1 = 2; y1 = 4; m = -1 in the equation above.
y - 4 = -1(x - 2)
Answer: y - 4 = -(x - 2)
y=mx+b is equation of a line
m= slope which is -1
b= y intercept which is 4
so, it would be y= -x+4
