Question

Look at this function:

Answer 1

Answer:

As x coordinate of function is : -6, -4, -2, 0

And y coordinate of function is : -13, -9, -5,-1

If a function is linear it means

Slope will be same everywhere.

Slope between two points$(x_{1},y_{1}) \text{and} (x_{2}, y_{2})$ is = $\frac{y_{2}-y_{1}}{x_{2} -x_{1}}$

= $\frac{-9+13}{-4+6}=\frac{4}{2}=2\\\frac{-5+9}{-2+4}=\frac{4}{2}=2\\\\\frac{-1+5}{0+2}=\frac{4}{2}=2\\\\\frac{-1+13}{0+6}=\frac{12}{6}=2$

So, between any two points slope are same i.e equal to 2.So it is a linear function.

So, Mark is right that the function is linear.

Answer 2

X values are increasing by 2
y values are increasing by 4
Mark is correct