Exercise 5 Page 123

Equations in slope-intercept form follow a certain format. y=mx+ b In this format m is the slope and b is the y-intercept. The line has a slope of - 2 which means that we can substitute m=- 2. y=- 2x+ b To write a complete equation for this line, we also need to determine the y-intercept b. We can do that by substituting the given point (- 3,8) into the equation and solving for b.

y=- 2x+b

SubstituteII

x= - 3, y= 8

8=- 2( - 3)+b

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Solve for b

MultNegNegOnePar

- a(- b)=a* b

8=6+b

SubEqn

LHS-6=RHS-6

2=b

RearrangeEqn

Rearrange equation

b= 2

Now that we have both the slope and the y-intercept, we can write the final equation. y=- 2x+ 2