SOLUTION: Hi. I really need help with the factoring trinomial problem 1/2x(x+20)=78. I've tried to answer it but I can't find the right factors for the numbers. This is as far as I got,
1/
Algebra ->
Polynomials-and-rational-expressions
-> SOLUTION: Hi. I really need help with the factoring trinomial problem 1/2x(x+20)=78. I've tried to answer it but I can't find the right factors for the numbers. This is as far as I got,
1/
Log On
Question 144725: Hi. I really need help with the factoring trinomial problem 1/2x(x+20)=78. I've tried to answer it but I can't find the right factors for the numbers. This is as far as I got,
1/2x(x+20)=78
1/2x(squared)+10x=78
1/2x(squared)+10x-78=0
Now, I'm not sure if before you subtract 78 you're supposed to divide by 1/2. So, I tried doing that and got,
x(squared)+10=156
x(squared)+10-156=0
After that I can't get the factors right. Please help.
Thank you! Answer by faceoff57(108) (Show Source):
You can put this solution on YOUR website! 1/2x(x+20)=78
2[ 1/2x(x+20)=78]
x(x+20)=156
x^2 + 20x = 156
x^2 + 20x - 156 = 0
(x - 6)(x + 26) = 0
x - 6 = 0
x = 6
x + 26 = 0
x = -26
x = 6 or -26
