Question

take a look at the original problem... what's the strategy?is the point (128,63) on the line above? if not whats the answer

Answer 1

We have the following:

We must determine the equation of the line on the graph, knowing that the equation in its slope and y-intercept form is the following

$\begin{gathered} y=mx+b \\ \text{where m is the slope and b is the y-intercept} \end{gathered}$

we calculate the slope as follows

The points are (4,1) and (-4,-3)

$m=\frac{y_2-y_1}{x_2-x_1}$

replacing

$m=\frac{-3-1}{-4-4}=\frac{-4}{-8}=\frac{1}{2}$

The y-intercept is (0, -1), therefore b is -1

Therefore, the equation is:

$y=\frac{1}{2}x-1$

To confirm if the point is there, we must replace the value of (128) in the equation and it must equal 63

$\begin{gathered} y=\frac{1}{2}\cdot128-1 \\ y=64-1 \\ y=63 \end{gathered}$

Which means that the point (128, 63) is in the line shown in the graph.