Question

Find an equation of the line passing through the pair of points (2,3) and (5,9). Write the equation in the form Ax + By = C.

Choose the correct answer below
A. X-2y = 1
B.- 2x + y = -1
C.- 2x +y = 4
D.x+y=4

Answer 1

- 2x + y = - 1 , so the B is correct.

Explanation:

+ Because of "the line passing through the pair of points (2,3) and (5,9)", that means the line has the equation y = ax + b where a = (9-3)/(5-2)= 6/3= 2

+ So the equation is y = 2x + b.

+ Then we replace x= 2 and y= 3 into y = 2x + b for finding like:

3 = 2*2 + b or 3 = 4 + b, so we find b = 3 - 4 = - 1.

+ The equation of this line is y = 2x - 1 or in the form:

2x - y - 1 = 0 (or -2x + y = -1)

Have a good day!