Question

Whats an approximate equation of a line that passes through the points (-4.3,2.3) and (1.3,-7.4)

Answer 1

Use the 2 points to find the gradient of the line
Gradient = (y - y1)/(x - x1), y and y1 are the two different y values.
(2.3 - - 7.4)/(-4.3 - 1.3) = -97/56 = -1.732
Note: y and x both come from the same coordinate, and y1 and x1 also come from the same coordinates - (x , y), (x1 , y1)

Use the following to find the equation (x, x1, y, and y1 are not the same as the first part)
y - y1 = m(x - x1)

Where x2 and y2 is an intersection (one of the coordinates you used) and m is the gradient you found.
So...
y - 2.3 = -1.732(x - - 4.3)
You can simplify this if you are required to.