Posted by Nabil on Monday, October 10, 2011 at 12:06am.
L = Length of a wire
x = Length of the first pice
y = Length of the cecond pice
x / 4 = Length of the first square
y / 4 = Length of the second square
L = 16 in
16 = x + y
y = 16 - x
Area of the first pice = ( x / 4 ) ^ 2
Area of the second pice = ( y / 4 ) ^ 2
( x / 4 ) ^ 2 + ( y / 4 ) ^ 2 = 10
x ^ 2 / 16 + y ^ 2 / 16 = 10
( x ^ 2 + y ^ 2 ) / 16 = 10 Multiply both sides with 16
x ^ 2 + y ^ 2 = 160
x ^ 2 + ( 16 - x ) ^ 2 = 160
( Remark: ( 16 - x ) ^ 2 = 16 ^ 2 - 32 x + x ^ 2
x ^ 2 + 16 ^ 2 - 32 x + x ^ 2 = 160
2 x ^ 2 + 256 - 32 x = 160
2 x ^ 2 + 256 - 160 - 32 x = 0
2 x ^ 2 + 96 - 32 x = 0
2 x ^ 2 - 32 x + 96 = 0 Divide both sides with 2
x ^ 2 - 16 x + 48 = 0
The exact solutions are:
x = 12
and
x = 4
Length of a wire = 16 in
y = 16 - x
When: x = 12 ; y = 16 - 12 = 4
When x = 4 ; y = 16 - 4 = 12
Length of the two pieces :
12 in
and
4 in
Proof:
( 12 / 4 ) ^ 2 + ( 4 / 4 ) ^ 2 = 10
3 ^ 2 + 1 ^ 2 = 10
9 + 1 = 10 in ^ 2
P.S.
If you don know how to solve equation:
x ^ 2 - 16 x + 48 = 0
In google type:
quadratic equation online
When you see list of results click on:
Free Online Quadratic Equation Solver:Solve by Quadratic Formula
When page be open in rectangle type:
x ^ 2 - 16 x + 48 = 0
and click option:
solve it!
You wil see solution step-by-step
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