This resource is for students to quickly explore equations of straight lines and how to find the gradient and y intercept.
(1)
y = mx + c is the function (or
equation of a straight line graph)
in gradient-intercept form
m is the gradient, and
c is the y intercept.
Graphical meaning of m and c shown in
https://www.geogebra.org/m/ssesmgqb
(2) Linear equations in the form
ax + by + c = 0,
ax + by = c or
by = ax + c (where a, b and c are real numbers)
can be reduced to their
equivalent equations in the gradient intercept form, ie y = mx + c.
(
additional self directed automated practices at
https://www.geogebra.org/m/fsgt7mp3
eg 4x + 2y - 6 = 0 ( of the form ax + by + c = 0)
2y = -4x + 6 (after subtracting 4x and adding 6 to both sides of the equation
y = -2x + 3 (after dividing both sides of the equation by 2)
which is of the form y = mx + c. (where m is the gradient and c is the y intercept)
y = -2x + 3 is the equivalent equation of 4x + 2y - 6 = 0 using the balance principle
of applying equal operations on both sides of an equation.
Hence for the graph represented by the linear equation 4x + 2y = 6 = 0,
the gradient of the graph is -2, and the y intercept is 3.
Using the balance principle x - 2y = 4 is equivalent to y = 0.5 x + 2
Hence, the gradient is 0.5 and the y intercept is 2.