Answer: y= -x + 7
Solution:
Step 1 : find the slope using the equation using the pair of coordinates that are given i.e A (−7,14) B (−21,28) ( name them A and B respectively so they can be easily named as x1, y1 and x2,y2 respectively)
m = y2-y1/x2-x1
m = 28-14 / -21 -( -7)
m = 14 / -14
m = -1
Step 2 : Find the y intercept using the line of equation (use and one of the given coordinates either A or B)
Using A ( -7, 14)
y= mx+ b
14 = (-1)(-7) + b
14= 7 + b
14-7 = b
7 =b
So,
y=mx+b
Insert m and b
y= -x + 7