Question

ion 8. The graph of a linear function passes through (-8,9) and (3, -13). Which is the equation for the function? A y = ext 13 5 5 B. y = -2x - 7 C. y = 4x + *** } D. y = -2x - 25

Answer 1

Step 1

We find the gradient(slope) of the graph using the formula below:

`\begin{gathered} m=(y_2-y_1)/(x_2-x_1) \\ =(-13-9)/(3-(-8)) \\ =(-22)/(11) \\ =-2 \\ \end{gathered}`

Step 2

We find the equation of the line using the formula below

`\begin{gathered} m=(y-y_1)/(x-x_1) \\ m=(y-9)/(x-(-8)) \\ m=(y-9)/(x+8) \\ \text{Cross multiply} \\ -2=(y-9)/(x+8) \\ -2(x+8)=y-9 \\ -2x-16=y-9 \\ y=-2x-16+9 \\ y=-2x-7 \\ \end{gathered}`

Therefore the answer is option B