Exercise 5 Page 240

We are given the slope and a point that lies on the line. This is enough information to write the equation in point-slope form. y-y_1=m(x-x_1) Let's do this first and then we will rewrite it in standard form. We can write the equation in point-slope form by substituting 3 for m and (1,6) for (x_1,y_1).

y-y_1=m(x-x_1)

Substitute

m= 3

y-y_1= 3(x-x_1)

SubstituteII

x_1= 1, y_1= 6

y- 6=3(x- 1)

Now that we have the equation in point-slope form, let's rearrange it until it is in standard form. Ax+By=C In the above formula, A, B, and C are constants. We will start by distributing 3.

y-6=3(x-1)

Distr

Distribute 3

y-6=3x-3

AddEqn

LHS+6=RHS+6

y=3x+3

SubEqn

LHS-3x=RHS-3x

y-3x=3

CommutativePropAdd

Commutative Property of Addition

- 3x+y=3

MultEqn

LHS * (-1)=RHS* (-1)

3x-y=-3

We have rewritten the equation of the line in standard form. 3x-y=-3 In this case, A=3, B=-1, and C=-3.