x and y Intercept - GRE Quantitative Reasoning

To find the -intercept, you need to find the value of the equation where . The easiest way to do this is to substitute in for your value of and see where you get for . If you do this for each of your equations proposed as potential answers, you find that is the answer.

Substitute in for :

If has a -intercept of , then it must pass through the point .

If its -intercept is , then it must through the point .

The slope of this line is .

Therefore, any line perpendicular to this line must have a slope equal to the negative reciprocal, which is . Only has a slope of .

Solve for so that the equation resembles the form. This equation becomes . In this form, the is the slope, which is .

To find the -intercept, you need to find the value of the equation where . The easiest way to do this is to substitute in for your value of and see where you get for . If you do this for each of your equations proposed as potential answers, you find that is the answer.

Substitute in for :

If has a -intercept of , then it must pass through the point .

If its -intercept is , then it must through the point .

The slope of this line is .

Therefore, any line perpendicular to this line must have a slope equal to the negative reciprocal, which is . Only has a slope of .

Solve for so that the equation resembles the form. This equation becomes . In this form, the is the slope, which is .

To find the -intercept, you need to find the value of the equation where . The easiest way to do this is to substitute in for your value of and see where you get for . If you do this for each of your equations proposed as potential answers, you find that is the answer.

Substitute in for :

If has a -intercept of , then it must pass through the point .

If its -intercept is , then it must through the point .

The slope of this line is .

Therefore, any line perpendicular to this line must have a slope equal to the negative reciprocal, which is . Only has a slope of .

The slope can be calculated from m = (y2 – y1)/(x2 – x1) = (6 – 1)/(5 + 2). Having calculated the slope, we can now use point-slope form of a line, y – y1 = m(x – x1), and using the second point (5, 6): y – 6 = (5/7)(x – 5). This can be rearranged into slope-intercept form to obtain: y = (5/7)x + (17/7). Because the equation is now in slope intercept form, we know that the y-intercept is 17/7.

The answer is 10.

In order to find the x-intercept we simply let all the y's equal 0

The key to these quantitative comparison problems is to figure out the worth of both quantities, or figure out whether evaluating the quantities is even possible. In this case, evaluating the quantities is a fairly straightforward case of figuring out the intercepts of two different lines, which is possible. Therefore, you can already discount "the relationship cannot be determined from the information given".

To solve quantity A: is in form, where is the -intercept. Therefore, the -intercept is equal to .

To solve quantity B: , you have to sole for the intercept. The quickest way to figure out the answer is to remember that the axis exists at the line , therefore to find out where the line crosses the axis, you can set and solve for .

-3.5 = .5x - 1.5

Both quantity A and quantity B , therefore the two quantities are equal.

To find the -intercept, you must plug in for .

This leaves you with

.

Then you must get you by itself so you add to both sides

.

Then divide both sides by to get

.

For the coordinate point, goes first then and the answer is .

The slope can be calculated from m = (y2 – y1)/(x2 – x1) = (6 – 1)/(5 + 2). Having calculated the slope, we can now use point-slope form of a line, y – y1 = m(x – x1), and using the second point (5, 6): y – 6 = (5/7)(x – 5). This can be rearranged into slope-intercept form to obtain: y = (5/7)x + (17/7). Because the equation is now in slope intercept form, we know that the y-intercept is 17/7.

The answer is 10.

In order to find the x-intercept we simply let all the y's equal 0

The key to these quantitative comparison problems is to figure out the worth of both quantities, or figure out whether evaluating the quantities is even possible. In this case, evaluating the quantities is a fairly straightforward case of figuring out the intercepts of two different lines, which is possible. Therefore, you can already discount "the relationship cannot be determined from the information given".

To solve quantity A: is in form, where is the -intercept. Therefore, the -intercept is equal to .

To solve quantity B: , you have to sole for the intercept. The quickest way to figure out the answer is to remember that the axis exists at the line , therefore to find out where the line crosses the axis, you can set and solve for .

-3.5 = .5x - 1.5

Both quantity A and quantity B , therefore the two quantities are equal.

To find the -intercept, you must plug in for .

This leaves you with

.

Then you must get you by itself so you add to both sides

.

Then divide both sides by to get

.

For the coordinate point, goes first then and the answer is .

The slope can be calculated from m = (y2 – y1)/(x2 – x1) = (6 – 1)/(5 + 2). Having calculated the slope, we can now use point-slope form of a line, y – y1 = m(x – x1), and using the second point (5, 6): y – 6 = (5/7)(x – 5). This can be rearranged into slope-intercept form to obtain: y = (5/7)x + (17/7). Because the equation is now in slope intercept form, we know that the y-intercept is 17/7.

The answer is 10.

In order to find the x-intercept we simply let all the y's equal 0

The key to these quantitative comparison problems is to figure out the worth of both quantities, or figure out whether evaluating the quantities is even possible. In this case, evaluating the quantities is a fairly straightforward case of figuring out the intercepts of two different lines, which is possible. Therefore, you can already discount "the relationship cannot be determined from the information given".

To solve quantity A: is in form, where is the -intercept. Therefore, the -intercept is equal to .

To solve quantity B: , you have to sole for the intercept. The quickest way to figure out the answer is to remember that the axis exists at the line , therefore to find out where the line crosses the axis, you can set and solve for .

-3.5 = .5x - 1.5

Both quantity A and quantity B , therefore the two quantities are equal.