Step-by-step explanation:
the typical line equation :
y = ax + b
with "a" being the slope, and b being the y-intercept (the y value when x = 0).
so, the equation starts
y = 1/2 x + b
to get b we use the given point coordinates :
1 = 1/2 × 4 + b = 2 + b
-1 = b
and the whole equation is
y = 1/2 x - 1
