Find the equation of the straight line which passes through the points (5, 0) and (6, 4).

We can use the general equation of a straight line to tackle this question: y=mx+c (m is the gradient and c is the y-intercept).(Note: The points are in the form (x, y).)
First, we will determine the gradient 'm'.
The gradient is another term for a slope, it determines how inclined the line joining two points is.To find out the value of the gradient, we need to calculate the ratio of the difference between the y values and the difference between the x values. The formula for this is m=(y1-y2)/(x1-x2).
In this case, we will take (5, 0) as the first point and (6, 4) as the second point. (i.e. x1 = 5, y1 = 0, x2 = 6, y2 = 4).So the gradient will be m = (0-4)/(5-6) = -4/-1 = 4.(Note: It doesn't matter which point we take as the first point and which point we take as the second point, as long as we are consistent in both the x and y values.)
Now that we have the gradient, we need to determine the value of the y-intercept 'c'.
To do this, we chose one of the points given to us. Let's say we choose (5, 0).We need to plug it into the generic equation y=mx+c with our calculated m value to get a value for c. (The value for c will be the same for any point on the line, so we can choose to use either of the points given to us in the question).
So with m=4, y=0 and x=5, we have0=(4)(5)+c0=20+cc=-20
This yields us out constant (unchanging no matter the coordinates) value of c as -20.
So our equation for this particular line is y=4x-20.
This is the solution to the question. We can now use this to determine any y value when we are given an x value, and to determine any x value when we are given a y value.
For example, if we were asked to find the y coordinate on this line where x=1,we would havey = 4(1)-20 = 4-20 = -16.
So our full coordinate would be (1, -16).

CM

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations: 4x+y=25 and x-3y=16


Minnie and Helen are playing in the same hockey match. The probability of Minnie scoring a goal is 0.3. The probability of Helen scoring a goal is 0.4. What is the probability of both Minnie and Helen scoring a goal.


Solve the following quadratic simultaneous equation: y = x + 4 and y = x^2 + 4x


Johnny take 4 hours 50 minutes to drive 213 miles to Manchester. He then takes the train to Liverpool. Liverpool is 37 miles from Manchester and the train travels at 90mph. Calculate Johnny's average speed for his total journey in mph.