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00jwaj

Member

Registered: 2011-05-02

Posts: 3

Quadratic expression word problem

The cumulative number of car accidents from 2000 to 2010 can be modeled by the quadratic expression C = -43x² + 1376x + 12040 where x=0 corresponds to 2000, x=1 corresponds to 2001 and so on until x=10 corresponds to 2010. Find the number of cumulative car accidents in 2005.
C = -43x² + 1376x + 12040
C = -43(0)² + 1376(0) + 12040
C = 0 + 0 + 12040
C = 12040 accidents in 2000

C = -43x² + 1376x + 12040
C = -43(1)² + 1376(1) + 12040
C = -43 + 1376 + 12040
C = 13373 accidents in 2001

C = -43x² + 1376x + 12040
C = -43(2)² + 1376(2) + 12040
C = -43*4 + 2752 + 12040
C = -52 + 2752 + 12040
C = 14620 accidents in 2002

C = -43x² + 1376x + 12040
C = -43(3)² + 1376(3) + 12040
C = -43*9 + 4128 + 12040
C = -387 + 4128 + 12040
C = 15781 accidents in 2003

C = -43x² + 1376x + 12040
C = -43(4)² + 1376(4) + 12040
C = -43*16 + 5504 + 12040
C = -688 + 5504 + 12040
C = 16856 accidents in 2004

C = -43x² + 1376x + 12040
C = -43(5)² + 1376(4) + 12040
C = -43*15 + 5504 + 12040
C = -688 + 5504 + 12040
C = 18,189 accidents in 2005

I'm going crazy I can't figure out where I keep going wrong. Can someone help me please?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Quadratic expression word problem

Hi;

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.