5 + 4x
I think that’s right
The correct answer would be 3, if im not mistaken
The answer is: 3.91 inches .
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Note: Volume of cylinder: V = (base area) * (height);
in which: V = volume = 384 in.³ ;
h = height = 8 in. ;
Base area = area of the base (that is; "circle") = π r² ;
in which; "r" = radius;
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Solve for "r" :
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V = π r² * (8 in.) ;
384 in.³ = (8 in.) * (π r²) ;
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Divide EACH SIDE of the equation by "8" ;
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(384 in.³) / 8 = [ (8 in.) * (π r²) in.] / 8 ;
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to get:
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48 in.³ = (π r²) in.² * in. ;
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↔ (π r²) in.² * in. = 48 in.³ ;
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Rewrite this equation; using "3.14" as an approximation for: π ;
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(3.14 * r²) in.² * in. = 48 in.³
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Divide EACH SIDE of the equation by:
"[(3.14)*(in.²)*(in.)]" ; to isolate "r² " on one side of the equation;
(since we want to solve for "r") ;
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→ [(3.14 * r²) in.² * in.] / [(3.14)*(in.²)*(in.)] = 48 in.³ / [(3.14)*(in.²)*(in.)] ;
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→ to get: r² = 48/3.14 ;
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→ r² = 15.2866242038216561 ;
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To solve for "r" (the radius; take the "positive square root" of EACH side of the equation:
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→ +√(r²) = +√(15.2866242038216561)
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→ r = 3.9098112747064475286 ; round to 3.91 inches .
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Add the three items he wants to buy:
4.95 + 9.10 + 5.50 = 19.55
Subtract how much he has already:
19.55 - 2.30 = 17.25
He needs $17.25 more
