Question 541275


{{{180w^2+300wf+125f^2}}} Start with the given expression.



{{{5(36w^2+60fw+25f^2)}}} Factor out the GCF {{{5}}}.



Now let's try to factor the inner expression {{{36w^2+60fw+25f^2}}}



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Looking at the expression {{{36w^2+60fw+25f^2}}}, we can see that the first coefficient is {{{36}}}, the second coefficient is {{{60}}}, and the last coefficient is {{{25}}}.



Now multiply the first coefficient {{{36}}} by the last coefficient {{{25}}} to get {{{(36)(25)=900}}}.



Now the question is: what two whole numbers multiply to {{{900}}} (the previous product) <font size=4><b>and</b></font> add to the second coefficient {{{60}}}?



To find these two numbers, we need to list <font size=4><b>all</b></font> of the factors of {{{900}}} (the previous product).



Factors of {{{900}}}:

1,2,3,4,5,6,9,10,12,15,18,20,25,30,36,45,50,60,75,90,100,150,180,225,300,450,900

-1,-2,-3,-4,-5,-6,-9,-10,-12,-15,-18,-20,-25,-30,-36,-45,-50,-60,-75,-90,-100,-150,-180,-225,-300,-450,-900



Note: list the negative of each factor. This will allow us to find all possible combinations.



These factors pair up and multiply to {{{900}}}.

1*900 = 900
2*450 = 900
3*300 = 900
4*225 = 900
5*180 = 900
6*150 = 900
9*100 = 900
10*90 = 900
12*75 = 900
15*60 = 900
18*50 = 900
20*45 = 900
25*36 = 900
30*30 = 900
(-1)*(-900) = 900
(-2)*(-450) = 900
(-3)*(-300) = 900
(-4)*(-225) = 900
(-5)*(-180) = 900
(-6)*(-150) = 900
(-9)*(-100) = 900
(-10)*(-90) = 900
(-12)*(-75) = 900
(-15)*(-60) = 900
(-18)*(-50) = 900
(-20)*(-45) = 900
(-25)*(-36) = 900
(-30)*(-30) = 900


Now let's add up each pair of factors to see if one pair adds to the middle coefficient {{{60}}}:



<table border="1"><th>First Number</th><th>Second Number</th><th>Sum</th><tr><td  align="center"><font color=black>1</font></td><td  align="center"><font color=black>900</font></td><td  align="center"><font color=black>1+900=901</font></td></tr><tr><td  align="center"><font color=black>2</font></td><td  align="center"><font color=black>450</font></td><td  align="center"><font color=black>2+450=452</font></td></tr><tr><td  align="center"><font color=black>3</font></td><td  align="center"><font color=black>300</font></td><td  align="center"><font color=black>3+300=303</font></td></tr><tr><td  align="center"><font color=black>4</font></td><td  align="center"><font color=black>225</font></td><td  align="center"><font color=black>4+225=229</font></td></tr><tr><td  align="center"><font color=black>5</font></td><td  align="center"><font color=black>180</font></td><td  align="center"><font color=black>5+180=185</font></td></tr><tr><td  align="center"><font color=black>6</font></td><td  align="center"><font color=black>150</font></td><td  align="center"><font color=black>6+150=156</font></td></tr><tr><td  align="center"><font color=black>9</font></td><td  align="center"><font color=black>100</font></td><td  align="center"><font color=black>9+100=109</font></td></tr><tr><td  align="center"><font color=black>10</font></td><td  align="center"><font color=black>90</font></td><td  align="center"><font color=black>10+90=100</font></td></tr><tr><td  align="center"><font color=black>12</font></td><td  align="center"><font color=black>75</font></td><td  align="center"><font color=black>12+75=87</font></td></tr><tr><td  align="center"><font color=black>15</font></td><td  align="center"><font color=black>60</font></td><td  align="center"><font color=black>15+60=75</font></td></tr><tr><td  align="center"><font color=black>18</font></td><td  align="center"><font color=black>50</font></td><td  align="center"><font color=black>18+50=68</font></td></tr><tr><td  align="center"><font color=black>20</font></td><td  align="center"><font color=black>45</font></td><td  align="center"><font color=black>20+45=65</font></td></tr><tr><td  align="center"><font color=black>25</font></td><td  align="center"><font color=black>36</font></td><td  align="center"><font color=black>25+36=61</font></td></tr><tr><td  align="center"><font color=red>30</font></td><td  align="center"><font color=red>30</font></td><td  align="center"><font color=red>30+30=60</font></td></tr><tr><td  align="center"><font color=black>-1</font></td><td  align="center"><font color=black>-900</font></td><td  align="center"><font color=black>-1+(-900)=-901</font></td></tr><tr><td  align="center"><font color=black>-2</font></td><td  align="center"><font color=black>-450</font></td><td  align="center"><font color=black>-2+(-450)=-452</font></td></tr><tr><td  align="center"><font color=black>-3</font></td><td  align="center"><font color=black>-300</font></td><td  align="center"><font color=black>-3+(-300)=-303</font></td></tr><tr><td  align="center"><font color=black>-4</font></td><td  align="center"><font color=black>-225</font></td><td  align="center"><font color=black>-4+(-225)=-229</font></td></tr><tr><td  align="center"><font color=black>-5</font></td><td  align="center"><font color=black>-180</font></td><td  align="center"><font color=black>-5+(-180)=-185</font></td></tr><tr><td  align="center"><font color=black>-6</font></td><td  align="center"><font color=black>-150</font></td><td  align="center"><font color=black>-6+(-150)=-156</font></td></tr><tr><td  align="center"><font color=black>-9</font></td><td  align="center"><font color=black>-100</font></td><td  align="center"><font color=black>-9+(-100)=-109</font></td></tr><tr><td  align="center"><font color=black>-10</font></td><td  align="center"><font color=black>-90</font></td><td  align="center"><font color=black>-10+(-90)=-100</font></td></tr><tr><td  align="center"><font color=black>-12</font></td><td  align="center"><font color=black>-75</font></td><td  align="center"><font color=black>-12+(-75)=-87</font></td></tr><tr><td  align="center"><font color=black>-15</font></td><td  align="center"><font color=black>-60</font></td><td  align="center"><font color=black>-15+(-60)=-75</font></td></tr><tr><td  align="center"><font color=black>-18</font></td><td  align="center"><font color=black>-50</font></td><td  align="center"><font color=black>-18+(-50)=-68</font></td></tr><tr><td  align="center"><font color=black>-20</font></td><td  align="center"><font color=black>-45</font></td><td  align="center"><font color=black>-20+(-45)=-65</font></td></tr><tr><td  align="center"><font color=black>-25</font></td><td  align="center"><font color=black>-36</font></td><td  align="center"><font color=black>-25+(-36)=-61</font></td></tr><tr><td  align="center"><font color=black>-30</font></td><td  align="center"><font color=black>-30</font></td><td  align="center"><font color=black>-30+(-30)=-60</font></td></tr></table>



From the table, we can see that the two numbers {{{30}}} and {{{30}}} add to {{{60}}} (the middle coefficient).



So the two numbers {{{30}}} and {{{30}}} both multiply to {{{900}}} <font size=4><b>and</b></font> add to {{{60}}}



Now replace the middle term {{{60fw}}} with {{{30fw+30fw}}}. Remember, {{{30}}} and {{{30}}} add to {{{60}}}. So this shows us that {{{30fw+30fw=60fw}}}.



{{{36w^2+highlight(30fw+30fw)+25f^2}}} Replace the second term {{{60fw}}} with {{{30fw+30fw}}}.



{{{(36w^2+30fw)+(30fw+25f^2)}}} Group the terms into two pairs.



{{{6w(6w+5f)+(30fw+25f^2)}}} Factor out the GCF {{{6w}}} from the first group.



{{{6w(6w+5f)+5f(6w+5f)}}} Factor out {{{5f}}} from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.



{{{(6w+5f)(6w+5f)}}} Combine like terms. Or factor out the common term {{{6w+5f}}}



{{{(6w+5f)^2}}} Condense the terms.



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So {{{5(36w^2+60fw+25f^2)}}} then factors further to {{{5(6w+5f)^2}}}



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Answer:



So {{{180w^2+300wf+125f^2}}} completely factors to {{{5(6w+5f)^2}}}.



In other words, {{{180w^2+300wf+125f^2=5(6w+5f)^2}}}.



Note: you can check the answer by expanding {{{5(6w+5f)^2}}} to get {{{180w^2+300wf+125f^2}}} or by graphing the original expression and the answer (the two graphs should be identical).



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