## motorcrossteamD21 3 years ago Factor 5a^3 + 15a^2 – 6a – 18 (a2 – 6)(5a + 3) (5a2 – 3)(a + 6) (5a2 – 6)(a + 3) (a2 + 6)(5a – 3)

1. bbnl1990

??

2. motorcrossteamD21

The stuff on the bottom is the choices for the answer. I need help on getting the answer, with someone factoring the problem.

3. bbnl1990

it's the 3rd one. Notice that it's the only one that will produce a (-6a) term. :)

4. motorcrossteamD21

Thank you:) Can you help with these other ones please? 18. The area of a rectangular barnyard is given by the trinomial 6x2 + 7x – 20. What are the possible dimensions of the barnyard? Use factoring. 2x – 5 and 3x + 4 –2x + 5 and –3x + 4 2x + 5 and 3x – 4 2x – 5 and 3x – 4 19. The area of a rectangular pool is given by the trinomial 2y2 + y – 3. What are the possible dimensions of the pool? Use factoring. (–y – 1) and (–2y – 3) (y – 1) and (2y + 3) (2y – 1) and (2y + 3) (2y + 1) and (y – 3) 20. A carpenter is putting a skylight in a roof. If the roof measures 10x + 9 by 7x + 7 and the skylight measures x + 5 by 3x + 3, what is the area of the remaining roof after the skylight is built? 67x2 + 115x + 48 73x2 + 151x + 78 70x2 + 133x + 63 3x2 + 18x + 15

5. bbnl1990

LOL. Alright im in the mood haha 18. c 19. b 20. you can do it!

6. motorcrossteamD21

Is it, c? Cause thats what I got when I worked it out.

7. bbnl1990

nope. the roof will will u a 70x^2 term, the skyline will give you a 3x^2 term, subtracting...

8. motorcrossteamD21

d?

9. bbnl1990

nope. its a. its Area(roof)-Area(skyline)

10. motorcrossteamD21

OH! I was working the opposite I think. I have one more question I need help with. A refrigerator has a volume given by the trinomial y3 + y2 – 56y. What are the possible dimensions of the refrigerator? Use factoring. y, y + 8, and y – 7 y, y – 8, and y + 7 y + 7, y + 7, and y – 7 y + 8, –y + 8, and –y + 7

11. bbnl1990

a. just a wild educated guess haha

12. bbnl1990

yeah. its a

13. motorcrossteamD21

Thank you so much! I give you a medal:)

14. bbnl1990

thanks! :)