Find the equation of the line that passes through ( 5 , -4 ) and (3,8).

The equation of a straight line takes the form of y=mx+c where m is the gradient of the line and c is the y-intercept (where the line crosses the y-axis). The best way to start this question is to draw a rough sketch of the line. Once this is done you would need to find the gradient and the y-intercept. The gradient is calculated by using the equation m= change in y/change in x. Therefore you would do the following calculation - m= (-4-8)/(5-3)=-6. The gradient (m) therefore is equal to -6. The y-intercept can be found in a couple of ways. First you would want to have a look at your diagram and see if the y-intercept is obvious. If this is not the case then you can find c by putting one set of the coordinates given into the equation. This would be done with the following calculation y=-6x+c this becomes 8=(-6*3)+c when we use the values from the coordinates (3,8). Then we rearrange the equation to obtain 26=c. The final solution to this question is y=-6x+26.