SOLUTION: I don't understand how to do trinomials. The problem is w^2+4w-84. The ^ means exponent.Could you please help me answer this question.

Algebra.Com
Question 119774This question is from textbook Algebra 2 with Trigonometry
: I don't understand how to do trinomials. The problem is w^2+4w-84. The ^ means exponent.Could you please help me answer this question. This question is from textbook Algebra 2 with Trigonometry

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
Do you want to factor?




Looking at we can see that the first term is and the last term is where the coefficients are 1 and -84 respectively.

Now multiply the first coefficient 1 and the last coefficient -84 to get -84. Now what two numbers multiply to -84 and add to the middle coefficient 4? Let's list all of the factors of -84:



Factors of -84:
1,2,3,4,6,7,12,14,21,28,42,84

-1,-2,-3,-4,-6,-7,-12,-14,-21,-28,-42,-84 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -84
(1)*(-84)
(2)*(-42)
(3)*(-28)
(4)*(-21)
(6)*(-14)
(7)*(-12)
(-1)*(84)
(-2)*(42)
(-3)*(28)
(-4)*(21)
(-6)*(14)
(-7)*(12)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to 4? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 4

First NumberSecond NumberSum
1-841+(-84)=-83
2-422+(-42)=-40
3-283+(-28)=-25
4-214+(-21)=-17
6-146+(-14)=-8
7-127+(-12)=-5
-184-1+84=83
-242-2+42=40
-328-3+28=25
-421-4+21=17
-614-6+14=8
-712-7+12=5

None of these pairs of factors add to 4. So the expression cannot be factored

RELATED QUESTIONS

Please help me with this problem. The perimeter of a rectangle is 84 feet. The legnth (answered by Paul)
Okay I really do not understand this chapter could you please help with this problem... (answered by stanbon)
In how many ways could five different envelopes be distributed into three mailboxes? The... (answered by ikleyn)
I REALLY NEED HELP! I DON'T UNDERSTAND HOW TO DO THIS PROBLEM. w+r/wr^2 +... (answered by vleith)
2 * 3^2x = 5 (The exponent on 3 is 2x.) I have the answer for this question but I do... (answered by ankor@dixie-net.com,MathLover1)
Could someone please check these, I am not sure if I understood them correctly. I should (answered by Alan3354)
This is factoring perfect Square trinomials, this is the problem, m^2 - 2m + 1 We are to (answered by stanbon,lwsshak3)
Here’s the problem: For a car renting for $15 per day plus $.10 per mile, the cost for (answered by stanbon)
I'm really having trouble with these few problems here and I can't call anyone from my... (answered by Earlsdon)