Exercise 8 Page 495

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 - 14 which means that we can substitute m=- 14. y=-1/4x+ 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 (- 8,- 5) into the equation and solving for b.

y=-1/4x+b

SubstituteII

x= - 8, y= - 5

- 5=-1/4( - 8)+b

▼

Solve for b

MultNegNegOnePar

- a(- b)=a* b

- 5=1/4* 8+b

MoveRightFacToNumOne

1/b* a = a/b

- 5=2+b

SubEqn

LHS-2=RHS-2

- 7=b

RearrangeEqn

Rearrange equation

b= - 7

Now that we have both the slope and the y-intercept, we can write the final equation. y=-1/4x+( - 7) ⇔ y=-1/4x - 7