SOLUTION: 23645=a(2)^2+b(2)+c 32015=a(20)^2+b(20)+c 33715=a(40)^2+b(40)+c When I tried to put this in quadratic form I got H=10t^2+245t+23115 From here I got stuck and couldn't figure

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: 23645=a(2)^2+b(2)+c 32015=a(20)^2+b(20)+c 33715=a(40)^2+b(40)+c When I tried to put this in quadratic form I got H=10t^2+245t+23115 From here I got stuck and couldn't figure       Log On


   

Question 379097: 23645=a(2)^2+b(2)+c
32015=a(20)^2+b(20)+c
33715=a(40)^2+b(40)+c
When I tried to put this in quadratic form I got
H=10t^2+245t+23115
From here I got stuck and couldn't figure out where to go. The assignment says to solve the quadratic formula.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
I'm not sure what you did.
Your solution is off.
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[A]=%28matrix%283%2C3%2C4%2C2%2C1%2C400%2C20%2C1%2C1600%2C40%2C1%29%29
[x]=%28matrix%283%2C1%2Ca%2Cb%2Cc%29%29
[b]=%28matrix%283%2C1%2C23645%2C32015%2C33715%29%29
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[A][x]=[b]
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Using matrix inversion,
a=-10
b=685
c=22315
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highlight%28H%28t%29=-10t%5E2%2B685t%2B22315%29
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Then using the quadratic formula,
t+=+%28-685+%2B-+sqrt%28+685%5E2-4%2A%28-10%29%2A22315+%29%29%2F%282%2A%28-10%29%29+
t+=+%28-685+%2B-+sqrt%28+469225%2B892600+%29%29%2F%28-20%29+
t+=+%28-685+%2B-+sqrt%28+1361825%29%29%2F%28-20%29+
t+=+%28-685+%2B-+5%2Asqrt%28+54473%29%29%2F%28-20%29+
t+=+%28-137+%2B-+sqrt%28+54473%29%29%2F%28-4%29+
highlight%28t+=+%28137+%2B-+sqrt%28+54473%29%29%2F%284%29%29+
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