SOLUTION: Please help me with this mproblem: (2x+120)(2x+53)=9000 I have this: 9000=4x^2+240x+106x+6360 9000-9000=4x^2+346x+6360-9000 0=4x^2+346x+2640 I'm stuck after that beca

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Please help me with this mproblem: (2x+120)(2x+53)=9000 I have this: 9000=4x^2+240x+106x+6360 9000-9000=4x^2+346x+6360-9000 0=4x^2+346x+2640 I'm stuck after that beca      Log On


   

Question 222115: Please help me with this mproblem:
(2x+120)(2x+53)=9000
I have this:
9000=4x^2+240x+106x+6360
9000-9000=4x^2+346x+6360-9000
0=4x^2+346x+2640
I'm stuck after that because I can't get it to divide evenly.
Thanks,
Zach
Found 4 solutions by checkley77, ptaylor, solver91311, Alan3354:
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
9000=4x^2+240x+106x+6360
9000-9000=4x^2+346x+6360-9000
0=4x^2+346x(-)2640 this term [2640] should be a negative value.
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
X=(-346+-SQRT[346^2-4*4*-2640])/2*4
X=(-346+-SQRT[119,716+42,240])/8
X=(-346+-SQRT[161,956])/8
X=(-346+-402.43757)/8
X=(-346+402.43757)/8
X=56.43757/8
X=7.055 ANS.
X=(-346-402.43757)/8
X=-748.43757/8
X=-93.555 ANS.

Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!

OK, ZACH, GOOD WORK!!!!!!!!!!!!! I GOT THE SAME THING THAT YOU GOT EXCEPT I GOT "-2640" AND YOU GOT "+2640". THERE'S NOTHING IN THE RULE BOOK THAT SEZ IT HAS TO DIVIDE EVENLY SO JUST GO AHEAD AT SOLVE IT USING THE QUADRATIC FORMULA.
(2x+120)(2x+53)=9000
4x^2+106x+240x+6360=9000
4x^2+346x-2640=0 divide each term by 2
2x^2+173x-1320=0 quadratic in standard form; solve using the quadratic formula

Hope this helps---=taylor

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


You have a sign error. Your equation should be:



Still, that is one mighty ugly quadratic, ugly with a capital EWWW. It won't factor, so you are stuck with either completing the square or using the quadratic formula. I would pick the latter.





Looks like you have some calculator work to do.

John

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
(2x+120)(2x+53)=9000
I have this:
9000=4x^2+240x+106x+6360
9000-9000=4x^2+346x+6360-9000
0=4x^2+346x+2640 *** - 2640, not +
2x^2 + 173x - 1320 = 0
It doesn't factor.
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B173x%2B-1320+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28173%29%5E2-4%2A2%2A-1320=40489.

Discriminant d=40489 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-173%2B-sqrt%28+40489+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28173%29%2Bsqrt%28+40489+%29%29%2F2%5C2+=+7.05469659982058
x%5B2%5D+=+%28-%28173%29-sqrt%28+40489+%29%29%2F2%5C2+=+-93.5546965998206

Quadratic expression 2x%5E2%2B173x%2B-1320 can be factored:
2x%5E2%2B173x%2B-1320+=+%28x-7.05469659982058%29%2A%28x--93.5546965998206%29
Again, the answer is: 7.05469659982058, -93.5546965998206. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B173%2Ax%2B-1320+%29