The straight line joining the points a(3,-5) and b(6,k) has a gradient of 4. work out the value of k.

The straight line joining the points A(3,-5) and B(6,k) has a gradient of 4.

Gradient is the slope

So the slope of the line joining the points A(3,-5) and B(6,k) is 4

Slope of line joining two points =

A(3,-5) and B(6,k) are (x1,y1)  and (x2,y2)

slope =

slope =

We know slope =4

Cross multiply  and solve for k

k + 5 = 12

k = 7

The value of k = 7

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value