The figure RQTS is a clockwise rotation of figure DEFC, then:
The image of CD is
Answer: Option C. RS
10x-5
You multiply each term in the parentheses by 5
4. Let the numbers be x - 2, x, and x + 2, where x is an odd number.
2(x² - 4) - 4x = (x + 2)² + 21
2x² - 8 - 4x = x² + 4x + 4 + 21
2x² - 4x - 8 = x² + 4x + 25
x² - 8x - 33 = 0
(x - 11)(x + 3) = 0
x = 11, or -3
When x = 11, x - 2 = 9, x + 2 = 13
When x = -3, x - 2 = -5, x + 2 = -1
Explanation: You are on the right track. However, rather than having three unknown variables, try to reduce your working out to one unknown variable. Since you know they are consecutive odd numbers, you can simply let x be the middle term and the other two be + and - 2, provided x is an odd number.
That will reduce your variable issues, and helps as the first and third provide a difference of two squares, and this works out very nicely.
Q5: is essentially the same process. Let your variables be something in the form of one unknown variable, and you should be okay from there. Let me know if you're stuck.
The correct answer is: [D]: "17" .
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The radius is: " 17" .
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Note:
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The formula/equation for the graph of a circle is:
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(x − h)² +<span> </span> (y − k)² = r² ;
in which:
" (h, k) " ; are the coordinate of the point of the center of the circle;
"r" is the length of the "radius" ; for which we want to determine;
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We are given the following equation of the graph of a particular circle:
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→ (x − 4)² + (y + 12)² = 17² ;
which is in the correct form:
→ " (x − h)² + (y − k)² = r² " ;
in which: " h = 4 " ;
" k = -12" ;
"r = 17 " ; which is the "radius" ; which is our answer.
→ { Note that: "k = NEGATIVE 12" } ;
→ Since the equation <u>for this particular circle</u> contains the expression: _________________________________________________________
→ "...(y + k)² ..." ;
[as opposed to the standard form: "...(y − k)² ..." ] ;
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→ And since the coordinates of the center of a circle are represented by:
" (h, k) " ;
→ which are: " (4, -12) " ; (<u>for this particular circle</u>) ;
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→ And since: " k = -12 " ; (<u>for this particular circle</u>) ;
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then:
" [y − k ] ² = [ y − (k) ] ² = " [ y − (-12) ] ² " ;
= " ( y + 12)² " ;
{NOTE: Since: "subtracting a negative" is the same as "adding a positive" ;
→ So; " [ y − (-12 ] " = " [ y + (⁺ 12) ] " = " (y + 12) "
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Note: The above explanation is relevant to confirm that the equation is, in fact, in "proper form"; to ensure that the: radius, "r" ; is: "17" .
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→ Since: "r = 17 " ;
→ The radius is: " 17 " ;
which is: Answer choice: [D]: "17" .
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