Question

Select the correct answer.

Which statement describes a relationship between these equations?
equation 1: y= 3x - 7
equation 2: y=-4x-7
O A.
The equations have the same y-intercept.
B.
The equations have the same slope.
OC.
Each equation represents a line that decreases from left to right.
OD.
Each equation represents a line that increases from left to right.

Answer 1

A. Yes they do. Both equations have their opposing set of y-intercept. Where equation one has a y-intercept of +7, and equation two, +7.

B. No they do not. Equation one has a slope of +3, while equation 2 has a slope of -4.

C. Yes they do. Equation one represents that of a positive increasing graph, while equation two the opposite, decreasing.

Explanation:

You can use the slope formula to identify and graph each equation simply by using y = mx + b. Where y is the the y coordinate, x is the x coordinate, m is the slope, and b is the y-intercept. With this you can start plotting by marking the y-intercept by putting the x as zero and seeing what number you get. In this case, 3x0-7 = -7. Meaning that would be the y-intercept. For the slope, depending on what the x coordinate is, that's how much the graph will increase or decrease whenever the x coordinate changes. Say the x coordinate is 1, so 3x1-7 = 3-7 = -4. Meaning your coordinate would be (1, -4) where you can keep doing this formula on and on to find the y coordinate for what x coordinate you want to find, or make it easier to graph with a ruler on paper once you have enough points.