Question 887717: please factor it!!!?
8x square + 5x - 200=0
Found 2 solutions by jim_thompson5910, Alan3354:
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website!
Looking at the expression  , we can see that the first coefficient is  , the second coefficient is  , and the last term is  .
Now multiply the first coefficient by the last term to get  .
Now the question is: what two whole numbers multiply to  (the previous product) and add to the second coefficient ?
To find these two numbers, we need to list all of the factors of (the previous product).
Factors of :
1,2,4,5,8,10,16,20,25,32,40,50,64,80,100,160,200,320,400,800,1600
-1,-2,-4,-5,-8,-10,-16,-20,-25,-32,-40,-50,-64,-80,-100,-160,-200,-320,-400,-800,-1600
Note: list the negative of each factor. This will allow us to find all possible combinations.
These factors pair up and multiply to .
1*(-1600) = -1600
2*(-800) = -1600
4*(-400) = -1600
5*(-320) = -1600
8*(-200) = -1600
10*(-160) = -1600
16*(-100) = -1600
20*(-80) = -1600
25*(-64) = -1600
32*(-50) = -1600
40*(-40) = -1600
(-1)*(1600) = -1600
(-2)*(800) = -1600
(-4)*(400) = -1600
(-5)*(320) = -1600
(-8)*(200) = -1600
(-10)*(160) = -1600
(-16)*(100) = -1600
(-20)*(80) = -1600
(-25)*(64) = -1600
(-32)*(50) = -1600
(-40)*(40) = -1600
Now let's add up each pair of factors to see if one pair adds to the middle coefficient :
| First Number | Second Number | Sum | | 1 | -1600 | 1+(-1600)=-1599 | | 2 | -800 | 2+(-800)=-798 | | 4 | -400 | 4+(-400)=-396 | | 5 | -320 | 5+(-320)=-315 | | 8 | -200 | 8+(-200)=-192 | | 10 | -160 | 10+(-160)=-150 | | 16 | -100 | 16+(-100)=-84 | | 20 | -80 | 20+(-80)=-60 | | 25 | -64 | 25+(-64)=-39 | | 32 | -50 | 32+(-50)=-18 | | 40 | -40 | 40+(-40)=0 | | -1 | 1600 | -1+1600=1599 | | -2 | 800 | -2+800=798 | | -4 | 400 | -4+400=396 | | -5 | 320 | -5+320=315 | | -8 | 200 | -8+200=192 | | -10 | 160 | -10+160=150 | | -16 | 100 | -16+100=84 | | -20 | 80 | -20+80=60 | | -25 | 64 | -25+64=39 | | -32 | 50 | -32+50=18 | | -40 | 40 | -40+40=0 |
From the table, we can see that there are no pairs of numbers which add to . So cannot be factored.
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Answer:
So doesn't factor at all (over the rational numbers).
So is prime.
To solve  you need to use the quadratic equation.
Answer by Alan3354(69443)  (Show Source):
You can put this solution on YOUR website! It's an equation. Equations are solved.
Polynomials are factored.
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please factor it!!!?
Is that a request, or a question? You have a ? on the end.
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