First you should know that y=mx+b
m = slope and b = y-intercept
You should start by finding the slope
Slope = y2 - y1 / x2 - x1 : (-7,46) and (-9,58) -7 = x1 , 46 = y1 , -9=x2, 58 =y2
58 - 46 / -9-(-7) = 12 / -2 m = -6
Now you need to find y-intercept
You can pick one of the two coordinates given (-7,46) and (-9,58)
I will pick (-9,58)
y = mx+b , you substitute the values in
58= -6(-9)+b we have to solve for b or y-intercept
58= 54 +b
b = 4
Answer would be y = -6x + 4