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Find the equation of the line passing through each pair of points. (Pic attached for (b) and (c))

Find the equation of the line passing through each pair of points. (Pic attached for-example-1

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Given two points (x₁, y₁) and (x₂, y₂), the slope of the line that passes through these two points can be calculated using the formula:


m=(y_2-y_1)/(x_2-x_1)\ldots(1)

Using an arbitrary point of the line (x₀, y₀), the slope-point form of the line equation is:


y-y_0=m(x-x_0)\ldots(2)

Now, from the problem:

(a)


\begin{gathered} (x_1,y_1)=(1,9) \\ (x_2,y_2)=(3,9) \end{gathered}

Using (1) to find the slope of the line:


\begin{gathered} m=(9-9)/(3-1) \\ \Rightarrow m=0 \end{gathered}

Now, using (1, 9) and (2):


\begin{gathered} y-9=0(x-1) \\ \Rightarrow y=9 \end{gathered}

The equation of the line is y = 9

(c)


\begin{gathered} (x_1,y_1)=(4.2,7.6) \\ (x_2,y_2)=(-1.6,9.1) \end{gathered}

Using (1) to find the slope of the line:


m=(9.1-7.6)/(-1.6-4.2)=(1.5)/(-5.8)=-(15)/(58)

Now, using (4.2, 7.6) and (2):


y-7.6=-(15)/(58)(x-4.2)

Rounding to two decimal places:


y=-0.26x+8.69

User Jagdish Idhate
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