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35 votes
35 votes
(2,7),(1,-4)write an equation for the line in point slope form .Then rewrite the equation in slope intercept form

User Will Da Silva
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1 Answer

19 votes
19 votes

Let's begin by listing out the information given to us:


\begin{gathered} (x_(1,)y_1)=(2,7) \\ (x_(2,)y_2)=(1,-4) \end{gathered}

Let's calculate the slope


m=(y_2-y_1)/(x_2-x_1)=(-4-7)/(1-2)=(-11)/(-1)=11

Slope = 11

Using point slope form, we have:


\begin{gathered} y-y_1=m(x-x_1) \\ y-y_2=m(x-x_2) \\ Using(1,-4) \\ y--4=11\left(x-1\right) \\ y+4=11x-11 \\ \text{Subtract 4 from both sides} \\ y=11x-15 \end{gathered}

Write the equation in slope intercept form, we have:

The general formula is given by y = mx + b

Let's calculate the slope


m=(y_2-y_1)/(x_2-x_1)=(-4-7)/(1-2)=(-11)/(-1)=11

The general formula becomes,

y = 11x + b

To solve for b, make b the subject formula, we have:

b = y - 11x

Substitute (2, 7) into the formula

b = 7 - 11 (2) = 7 - 22 = -15

b = -15

Substitute the value of b into the formula y = 11x + b, we have:


y=11x-15

User Fabrice MARIANADIN
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