SOLUTION: Hey. I'm having trouble understanding what to do in these problems. I know the answers are YES and 0, but i dont get why. I would very much appreciate if you could help. a. A te

Algebra ->  Problems-with-consecutive-odd-even-integers -> SOLUTION: Hey. I'm having trouble understanding what to do in these problems. I know the answers are YES and 0, but i dont get why. I would very much appreciate if you could help. a. A te      Log On


   



Question 1060610: Hey. I'm having trouble understanding what to do in these problems. I know the answers are YES and 0, but i dont get why. I would very much appreciate if you could help.
a. A teacher sees the following factoring on a student's paper. Is this factoring correct?
4(x - 3)2 - 8(x - 3) = 4(x - 3)[(x - 3) - 2] = 4(x - 3)(x - 5)
Choose:
-YES
-NO
b. What is the value of 4(x - 3)2 - 8(x - 3) - 4(x - 3)(x - 5)? (take note that the dash i added was to divide the answers, not negatives, which is why i left a space between the number)
Choose:
- 1
- 0
- -12x + 44
- 24x + 48

Answer by CubeyThePenguin(3113) About Me  (Show Source):
You can put this solution on YOUR website!
4(x-3)^2 - 8(x-3)
= 4(x-3)(x-3) - 8(x-3)
= 4(x-3)((x-3) - 2)
= 4(x-3)(x-5)

4(x-3)^2 - 8(x-3) - 4(x-3)(x-5)
= 4(x^2 - 6x + 9) - (8x - 24) - 4(x^2 - 8x + 15)
= (4x^2 - 24x + 36) - 8x + 24 - 4x^2 + 32x - 60
= -24x + 36 - 8x + 24 + 32x - 60
= 0