A line passes through the points (-2,1) and (4,4). Find the equation of the line in the form y = mx + c

In the form y = mx + c, m stands for the slope (or gradient) of the line, and c for its y-intercept. Since we are given two points that are on the line, we can figure out its slope by looking at the vertical and horizontal distance between the two points. Remember that the first coordinate expresses how far right or left a point is, and the second coordinate expresses how far up or down a point is. To get from (-2,1) to (4,4) the line rises a vertical distance of 4 - 1 = 3. So our RISE = 3. The line runs or covers a horizontal distance of 4 - (-2) = 6 between the two points. So our RUN = 6. The slope of the line is simply RISE divided by RUN, or m = 3/6 = 1/2. We now have y = 1/2 x + c. The easiest way to figure out the y-intercept c is to substitute the coordinates of a known point on the line into that equation. Taking for example point (4,4): 4 = 1/2 * 4 + c . We now simply need to rearrange for c: 4 = 2 + c --> c = 2 The solution is then: y = 1/2 x + 2

Answered by Filip B. Maths tutor

3161 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

each month Rohan spends all his income on rent, travel and other living expenses. 1/3 of his income is used for rent, 1/5 on travel and £420 on other living expenses ... work out his income each month


Write down the value of (125)^2/3


expand and simplify (x+7)(2x+4)


A right-angled triangle has an angle of 30 degrees and its hypotenuse has a length of 9cm. Find the length of either of the triangle's other two sides.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences