Please give a picture so I can see
3x - y + z = 5 . . . (1)
x + 3y + 3z = -6 . . . (2)
x + 4y - 2z = 12 . . . (3)
From (2), x = -6 - 3y - 3z . . . (4)
Substituting for x in (1) and (3) gives
3(-6 - 3y - 3z) - y + z = 5 => -18 - 9y - 9z - y + z = 5 => -10y - 8z = 23 . . (5)
-6 - 3y - 3z + 4y - 2z = 12 => y - 5z = 18 . . . (6)
(6) x 10 => 10y - 50z = 180 . . . (7)
(5) + (7) => -58z = 203
z = 203/-58 = -3.5
From (6), y - 5(-3.5) = 18 => y = 18 - 17.5 = 0.5
From (4), x = -6 - 3(0.5) - 3(-3.5) = -6 - 1.5 + 10.5 = 3
x = 3, y = 0.5, z = -3.5
Answer: The dimensions are: " 1.5 mi. × ³⁄₁₀ mi. " .
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{ length = 1.5 mi. ; width = ³⁄₁₀ mi. } .
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Explanation:
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Area of a rectangle:
A = L * w ;
in which: A = Area = (9/20) mi.² ,
L = Length = ?
w = width = (1/5)*L = (L/5) = ?
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A = L * w ; we want to find the dimensions; that is, the values for
"Length (L)" and "width (w)" ;
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Plug in our given values:
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(9/20) mi.² = L * (L/5) ; in which: "w = L/5" ;
→ (9/20) = (L/1) * (L/5) = (L*L)/(1*5) = L² / 5 ;
↔ L² / 5 = 9/20 ;
→ (L² * ? / 5 * ?) = 9/20 ?
→ 20÷5 = 4 ; so; L² *4 = 9 ;
↔ 4 L² = 9 ;
→ Divide EACH side of the equation by "4" ;
→ (4 L²) / 4 = 9/4 ;
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to get: → L² = 9/4 ;
Take the POSITIVE square root of each side of the equation; to isolate "L" on one side of the equation; and to solve for "L" ;
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→ ⁺√(L²) = ⁺√(9/4) ;
→ L = (√9) / (√4) ;
→ L = 3/2 ;
→ w = L/5 = (3/2) ÷ 5 = 3/2 ÷ (5/1) = (3/2) * (1/5) = (3*1)/(2*5) = 3/10;
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Let us check our answers:
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(3/2 mi.) * (3/10 mi.) =? (9/20) mi.² ??
→ (3/2)mi. * (3/10)mi. = (3*3)/(2*10) mi.² = 9/20 mi.² ! Yes!
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So the dimensions are:
Length = (3/2) mi. ; write as: 1.5 mi.
width = ³⁄₁₀ mi.
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or; write as: " 1.5 mi. × ³⁄₁₀ mi. " .
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Answer: -2
Step-by-step explanation:
