w Practice and Problem-Solving Exercises
Practice Find the x- and y-intercepts of the graph of each equation.- x + y = 9 9. x-2y= 2
- 3x — 5 y = —20 12. 7x-y = 21
Draw a line with the given intercepts.- x-intercept: - 1
y-intercept: - 4 - x-intercept: 3
y-intercept: 5
Graph each equation using x- and y-intercepts.
17.x + y = 4 18.x + y = - 3
- 2 x + y = 8 21. —4x + y = —12
4P See Problem 1.- —3x + 3y = 7
- 5 x + 3y= -7.5
See Problem 2.- x-intercept: 4
y-intercept: - 3 - x - y = —8
- 6 x - 2 y = 18
For each equation, tell whether its graph is a horizontal o r a vertical line.- y=-4 24. x = 3 25. y — \
Graph each equation.- y = 6 28. x= -3 29. y= -2
Write each equation in standard form using integers.- y = 2x + 5 32. y + 3 = 4 ( x - 1) 33. y
See Problem 3.- x= -1.8
- x=7
See Problem 4.
4 = —2(x — 3)- y = jx -2 35. y = —~ x - 1 36. y + 2 = f(x + 4)
- Video Games In a video gam e, you ea rn 5 points for each jew el you find. You See Problem 5.
earn 2 points for each star you find. W rite an d graph an e q u a tio n th a t represents
th e n u m b ers of jewels an d stars you m u st find to ea rn 250 points. W hat are three
com binations of jewels an d stars you can find th a t will ea rn you 250 points? - Clothing A store sells T-shirts for $12 each an d sw eatshirts for $15 each. You
plan to sp en d $120 on T-shirts an d sw eatshirts. W rite an d graph an equ atio n th at
represents this situation. W hat are th ree com binations of T-shirts a n d sw eatshirts
you can buy for $120?
Apply 39. Writing The th ree forms of linear eq u atio n s you have studied are slope-intercept
form, point-slope form, an d stan d ard form. Explain w h en each form is m ost useful. - Think About a Plan You are p rep arin g a fruit salad. You w an t th e total
carbohydrates from p in eap p le a n d w aterm elon to equal 24 g. P ineapple has 3 g of
carbohydrates p er o unce a n d w aterm elon has 2 g of carbohydrates p er ounce. W hat
is a graph th a t shows all possible com binations of ounces of p in eap p le a n d ounces
of watermelon?- Can you write an eq u a tio n to m odel the situation?
- W hat do m ain a n d range are reasonable for th e graph?
326 Ch ap t er 5 Li n ear Fu n ct io n s