Answer:
y = -2x +5
Explanation:
standard equation of any line is y=ax+b
since you have coordinates of 3 points substitute the coordinates to find a and b.
1st : 3 = a (1) + b >>> a + b = 3 >>> a = 3 - b
2nd : 1 = a (2) + b >>> 2a + b = 1 >>> substitute a with (3-b)
2 ( 3-b ) + b = 1 >>> 6 - 2b + b = 1 >>> -b = 1-6=-5 >>> b = 5
a = 3 - 5 = -2
equation is y = -2x + 5