Question

What is the equation of this line?

Answer 1

Answer:

All you have is the y intercept ( the point at which the graph crosses the y-axis

Step-by-step explanation:

but you need further information

Lets suppose y= mx + c , you know that y = -2 at a certain point.

-2 = mx + c

to calculate the slope m , you need to know 2 points (x1,x2) , (y1, Y2)

Answer 2

Answer:

y = (1/2)x - 3     Answer A is closest.  

Step-by-step explanation:

Two points on the line are (0, -3) and (4, -1).  Notice that I've intentionally chosen "nice" points whose coordinates are integers; this makes the math easier.  The point (1, -5/2) is also on the line if you want to use it, but the math's a bit more complicated.

Going from (0, -3) to (4, -1), x increases by 4 and y increases by 2.  Hence, the slope of this line is m = rise / run = 2/4, or m = 1/2.

The slope-intercept formula for the equation of a straight line is the most convenient to use here, since we can tell immediately from the graph that the y-intercept is (0, -3):

y = (1/2)x - 3

Answer A should be y = (1/2)x - 3 for improved legibility.  1 2 x is not correct as a way to express (1/2)x.