Question 73752
Since this is a linear equation (it is a line) the points (0,1), (4,9), (3,N) will all be on the same line. So lets find the equation for the line through the points (0,1), (4,9). First we need the slope
*[invoke calculating_slope 0, 1, 4, 9]
Now use the slope and the point (0,1) to find the equation.
{{{y-y[1]=m(x-x[1])}}}Plug in m=2 and (0,1)
{{{y-1=2(x-0)}}}
{{{y=2x+1}}}
So any more solutions will lie on this line. So to find N, just plug in x=3 to find y
{{{y=2(3)+1}}}
{{{y=6+1}}}
{{{y=7}}}
So the solution is (3,7) which supports the answer. Hope this makes sense. Draw the graph and the points if this is hard to understand.