Question

This table gives a few (x, y) pairs of a line in the coordinate plane. х у -28 - 54 -21 -40 - 14 -26 What is the y-intercept of the line?

Answer 1

with this table we can calculate the slipe of the line that is:

`\begin{gathered} m=(18-24)/(-74-(-94)) \\ m=(-6)/(20)=-(3)/(10) \end{gathered}`

now with the equation of the line and a pait of coordinates we can find the y-intercept so:

`\begin{gathered} 24=-(3)/(10)(-94)+b \\ 24-28.2=b \\ -4.2=b \end{gathered}`

SO the equation of the line is:

`y=-(3)/(10)x-4.2`

So to find the x-intercept we replace y = 0 so:

`\begin{gathered} (3)/(10)x=-4.2 \\ x=(-4.2\cdot10)/(3) \\ x=-14 \end{gathered}`

So the order pair is:

`(-14,0)`