Question

What is the equation of the line?A. y=3/4x−1 B.y=4/3x+1 C.y=3/4x+1 D.y=4/3x−1

Answer 1

B. y = 4/3x + 1

Explanation:

First, find the slope using rise/run (y2 - y1) / (x2 - x1)

Use the points (0, 1) and (3, 5)

Plug in the numbers:

(5 - 1) / (3 - 0)

= 4/3

Looking at the graph, we can see the y intercept is (0, 1) so we can plug in 1 into the equation y = mx + b as b:

y = mx + b

y = 4/3x + 1

Answer 2

B. y = 4/3x + 1

Explanation:

The offered choices are in slope-intercept form:

y = mx + b

where m represents the slope (rise/run) and b represents the y-intercept.

The graph crosses the y-axis at y=1, so the y-intercept is +1. That eliminates choices A and D.

The slope is greater than 1, so choice C is eliminated. You know the slope is greater than 1 because the line goes up more than 1 unit for a 1-unit change to the right. If you look where the line crosses grid points, you see that it rises 4 units for a run of 3 units to the right. That means ...

m = rise/run = 4/3

The equation is ...

y = 4/3x +1 . . . . matches choice B