SOLUTION: Can you help me with this? Fill in the blanks. a) {{{14x^2-21=(______)(2x^2-3)}}} b) {{{3x^2+5x-28=(___________ )(x+4)}}} Thank you!

Algebra ->  Expressions-with-variables -> SOLUTION: Can you help me with this? Fill in the blanks. a) {{{14x^2-21=(______)(2x^2-3)}}} b) {{{3x^2+5x-28=(___________ )(x+4)}}} Thank you!      Log On


   

Question 286538: Can you help me with this?
Fill in the blanks.
a) 14x%5E2-21=%28______%29%282x%5E2-3%29
b) 3x%5E2%2B5x-28=%28____________%29%28x%2B4%29
Thank you!
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
Factor out the common value 7 from each term.
14x^2-21=7(x^2-3)
a) 14x%5E2-21=%287%29%282x%5E2-3%29
Factor the equation:
Factor 3x^3=3x & x
Factor -28=-7 & 4
Now combine the terms.
(3x-7)(x+4)
Prove using the FOIL technique.
3x^2-7x+12x-28
3x^2+5x-28
b) 3x%5E2%2B5x-28=%283x-7%29%28x%2B4%29