Answer:
y = -1/2x - 5
Step-by-step explanation:
To solve this (and questions like it), use the formula for the equation of a line:
y=mx+c, where y and x are any given co-ordinates, m is the slope, and c is the y-intercept.
Since we know that the slope is -1/2, we can plug this into our equation to replace m:
y=mx+c
y=-1/2x+c
To find c, we plug in our co-ordinate (4,-7), so that c is the only unknown, and we can solve for it:
y=-1/2x+c
-7=-1/2(4)+c
-7=-2+c
c=-5
Now that we know c, we can finish off our equation:
y = -1/2x + c
y = -1/2x - 5
