Mathematics
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OpenStudy (anonymous):
It says to Simplify the expression to lowest terms.
4x^2-9
-------
2x^2+11x+12
I don't understand how to do this.
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OpenStudy (anonymous):
@dan815
OpenStudy (anonymous):
@Compassionate
OpenStudy (anonymous):
@wio @skullpatrol
OpenStudy (anonymous):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
hint:
factor 4x^2-9 to get (2x-3)(2x+3)
we use the difference of squares rule here
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jimthompson5910 (jim_thompson5910):
also try to factor 2x^2+11x+12
OpenStudy (anonymous):
Is the bottom (x+4) ? so it would be 2x+3/x+4
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
not quite
jimthompson5910 (jim_thompson5910):
multiply the first coefficient and the last term to get: 2*12 = 24
what two numbers multiply to 24 AND add to 11 (middle coefficient)?
OpenStudy (anonymous):
8 and 3?
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OpenStudy (anonymous):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
so 11x = 8x + 3x
jimthompson5910 (jim_thompson5910):
then we factor by grouping
jimthompson5910 (jim_thompson5910):
2x^2+11x+12
2x^2+8x+3x+12
(2x^2+8x)+(3x+12)
2x(x + 4) + (3x+12)
2x(x + 4) + 3(x + 4)
(2x + 3)(x + 4)
jimthompson5910 (jim_thompson5910):
So that means 2x^2+11x+12 factors to (2x + 3)(x + 4)
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jimthompson5910 (jim_thompson5910):
oh and nvm, i misread
jimthompson5910 (jim_thompson5910):
it looks like you have the right answer
jimthompson5910 (jim_thompson5910):
actually, it should be
\[\Large \frac{2x-3}{x+4}\]
jimthompson5910 (jim_thompson5910):
not 2x+3 in the numerator
jimthompson5910 (jim_thompson5910):
since the 2x+3 terms will cancel
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OpenStudy (anonymous):
Okay, thanks for the help!
jimthompson5910 (jim_thompson5910):
yw