The first one:
x + (x+ 1) = 143
2x + 1 = 143
2x = 142
x= 71
so the numbers are 71 and 72.
2007-02-26 01:36:39
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answer #1
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answered by crzywriter 5
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1) n* (n+2) = 143
n^2 +2n - 143 = 0
(n-11)*(n+13) = 0
(n+13) = 0 n = -13 doesn't make sense
(n-11) = 0 N = 11 N+2 = 13
11 and 13
2) 20 + n^2 = 12*n
n^2 - 12n +20 = 0
(n-2) * (n-10)
n = 2 4 +20 = 12 * 2 yes
n = 10 100 +20 = 12 * 10 yes
both 2 and 10 are good answers
3) ( n+3) * (n-2) = 14
n^2 +n - 20 = 0
(n-4) * (n+5) = 0
n=4
check (4+3) * (4-2) = 14
7 * 2 = 14 yes
the number is 4
4) n^2 + (n+2)^2 = 202
n^2 + n^2 + 4n + 4 = 202
2n^2 + 4n + 4 =202
n^2 +2n + 2 = 101
n^2 +2n -99 = 0
(n+11) * (n-9)=0
n=9 n+2 = 11 check 81 + 121 = 202 yes
5) n* (n+2)) = 288
n^2 + 2n -288 = 0
(n+18) * (n-16) = 0
n = 16 and n+2 = 18 check 16*18 = 288 yes
2007-02-26 02:04:10
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answer #2
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answered by bob_whelan1944 3
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Most of these are trial and error, you just have to know what the terms mean and a few basic equations. Consecutive means next to each other.
1)xy=143 (11 &)
2)(2)
3)2x+3=14+x (x=11)
4)x^2+y^2=202 (9 &)
5)xy=288 (16 &)
Hope that helps at least.
2007-02-26 01:58:29
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answer #3
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answered by Terra S 1
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heres a start:
1)let x be the first ODD integer and x+2 be the second ODD integer. product means multiply.
therefore your new equation is x(x+2)=143.
distribute the x. (x^2+2x) =143
set =0, x^2+2x-143=0
factor. multiples of 143 are (1,143)(11,13)
so the answer is 11,13 because they are consecutive odd integers.
2) let x= a number, therefore your new equation is
x^2+20=12x
set equal to 0 to solve for x...x^2-12x+20=0,
Factor. find multiples of 20...(1, 20)(2,10)(4,5)...
since the equation says +20 that means signs are like (either both + or both -) given that its -12, we know that 2,10 are the only multiples that when added give us -12, therefore you now have
(x-10)(x-2)=0, x-10=0 and x-2=0
therefore x=10 and x=2
3)let x=a number, therefore your new equation is:
(x+3)(x-2)=14
FOIL. x^2+3x-2x-6=14.
combine like terms. x^2+x-20=0
factor. multiples of 20 are (1,20)(2,10)(4,5). since its -20 we know signs are differrent. since its +1 we will use 5 as the positive value.
so after factoring we now have
(x+5)(x-4)=0, set each =0
x+5=0 and x-4=0, therefore x=-5 and x=4
now you try the remaining problems...if you still need help, you can email me at gebny1211@aim.com and i will help you.
2007-02-26 01:48:38
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answer #4
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answered by xtcwmeg 3
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Suppose x is the required no.
From the given data,
x^2 + 20 = 12x
x^2 - 12x + 20=0
(x-10)(x-2)=0
x=10 or x=2
2007-02-26 01:51:02
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answer #5
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answered by jalpa c 2
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Henry, to solve these problems, call your unknown "x" and set up an equation to represent each of the problems. I'll do no.1
x (x+2)= 143
x(squared) +2x =143
x (squared)+2x-143=0
(x -11 )(x+13)=0
x=11 (Proof: 11 x 13 =143)
You may try the others on your own. If I do them, it won't help you learn very much.
2007-02-26 01:44:58
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answer #6
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answered by cottagstan 5
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the answers in
#1 is 71, 72
#4 is 9 & 11
#5 is 14 & 16
i cant understand the 2nd and 3rd questions.. very confusing.
2007-02-26 01:56:20
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answer #7
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answered by jerome 1
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1) 11 and 13;
2) 2 and 10;
3)
4)
5) 16 and 18
2007-03-06 01:06:49
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answer #8
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answered by Anonymous
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cheaters never prosper. even cheaters who use Yahoo! to answer their homework. ive learned my lesson.
2007-03-02 11:28:05
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answer #9
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answered by Sierra 3
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