Question

Which of the following equations represent(s) a line that goes through the

points (2,3) and (1,1)?
1) y = 2(x-2) + 3
II) y = 2x - 1
III) y = 2(x-1) + 1
O I, II & III
O III only
OI and III
OI only
O II only

Answer 1

O I, II & III

Explanation:

(2, 3) and (1, 1)

m = (3 - 1)/(2 - 1) = 2

y = 2x + b

1 = 2(1) + b

b = -1

The equation of the line is

y = 2x - 1

I) y = 2(x - 2) + 3 = 2x - 4 + 3 = 2x - 1 Yes

II) y = 2x - 1 Yes

III) y = 2(x - 1) + 1 = 2x - 2 + 1 = 2x - 1 Yes

Answer: O I, II & III