Question 630606: Hello
I have couple questions.
1) what is the exact values of x^2+4x-20=0
and how can I find it
2)a floor measures 12m by 8m. a rug covers one-third of the floor.the uncovered part of the floor forms a uniform strip around the rag . how wide is the strip ?
Thanks for helping
Found 2 solutions by stanbon, 55305:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1) what is the exact values of x^2+4x-20=0
and how can i find it?
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Factor:
x = [-4 +- sqrt(16-4*-20)]/2
x = [-4 +- sqrt(96)]/2
x = [-4 +- 4sqrt(6)]/2
x = -2 + 2sqrt(6) or x = -2 - 2sqrt(6)
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2)a floor measures 12m by 8m. a rug covers one-third of the floor.the uncovered part of the floor forms a uniform strip around the rug . how wide is the strip ?
Draw a picture of a rectangle inside a rectangle.
Area of the outer rectangle including the area of the inner: 12m x 8m = 96 m^2
Area outside the inner and inside the outer rectangle: (1/3)96 = 32 m^2
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Dimensions of that area: (12-2x)(8-2x) = 32 m&3
96-40x+4x^2 = 32
x^2 - 10x + 24 = 0
(x-6)(x-4) = 0
x = 4m (width of the strip)
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Cheers,
Stan H.
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Answer by 55305(86) (Show Source):
You can put this solution on YOUR website! 1)
| Solved by pluggable solver: EXPLAIN simplification of an expression |
Your Result:
YOUR ANSWER
- This is an equation! Solutions: x=2.89897948556636,x=-6.89897948556636.
- Graphical form: Equation
 was fully solved. - Text form: x^2+4x-20=0 simplifies to 0=0
- Cartoon (animation) form:
For tutors: simplify_cartoon( x^2+4x-20=0 )
- If you have a website, here's a link to this solution.
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DETAILED EXPLANATION
Look at  .
Equation  is a quadratic equation: x^2+4*x-20 =0, and has solutions 2.89897948556636,-6.89897948556636
It becomes  .
Result: 
This is an equation! Solutions: x=2.89897948556636,x=-6.89897948556636.
Universal Simplifier and Solver
Done!
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2) First lets find the area of the rug. To do that, we must find the area of the floor and then find 1/3 of that. So 12*8=96 and 1/3 of that is 32. So if we look at the factors of 32, 1,2,4,8,16,32, then we can see that dimensions of the rug can only 4m*8m because those are the only numbers that are smaller than the dimensions of the floor. So the length of the strip is 2m (not 4 because the uniform strip of floor goes around the rug).
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