This is number problem 10 solution which read:
"Find 3 consecutive even integers such that 4 times the first is decreased by the second is 12 more than twice the third. " Ok I'm not understading the "is decreased by the" part so I assume it was a typo and you just meant "Find 3 consecutive even integers such that 4 times the first is 12 more than twice the third. "
ok 3 consecutive even integers would b x, x + 2, and x + 4
4 times the 1st would be just 4x and is equal to 12 more than twice the 3rd which would be (x + 4) * 2 + 12
which is... 4x = (x+4)*2 + 12
4x = 2x + 8 + 12
2x = 20
x = 10 So the answer would be 10, 12, 14 to check 4(10) = (14)*2 + 12
40 = 28 + 12
40 = 40
Thursday, November 25, 2010
Number Problem 10 Solution
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maybe it should be this way
ReplyDeletex=1st integer
x+2= 2nd integer
x+4= 3rd integer
4x-x+2=12+(x+4)2
3x+2=12+2x+8
3x+2=20+2x
3x-2x=20-2
x = 18
but im not really sure w/ dis one
it can't be 18 cuz
Delete4*18=72
18+4=22
22*2=44
44+12=56
72 doesn't=56
The question doesn't make sense as written i think it was a typo so i just solved the question i think they meant to say.
ReplyDeleteThis question is bad. I got a different answer to both the poster and the commenter above.
ReplyDeletex, x + 2, x + 3
"4 times the first is decreased by the second" -
4x - (x + 2)
"is 12 more than twice the third"
4x - (x + 2) = 2(x + 4) + 12
4x - x - 2 = 2x + 8 + 12
3x - 2 = 2x + 20
x = 22
Validating -
4(22) - (22 + 2) = 2(22 + 4) + 12
88 - 22 - 2 = 44 + 8 + 12
64 = 64
Hope this helps.
- Damon
"4 times the first is decreased by the second" --- -is too vague -- in my problem i corrected it to what i believe the poster meant to ask it and makes more sense as a question and thus the answer but thanks for your input though...
ReplyDeleteWrong translation sir...
ReplyDeleteYou translate sir.
ReplyDeleteyup...
ReplyDeletetypo...
I hate typos.. lol
ReplyDeletethis site is the best
ReplyDeleteThanks for the positive input!
ReplyDeleteI agree with the one who answered 22, 24, 26 coz we've got the same answer and checking, re stating the problem as "Find 3 consecutive even integers such that 4 times the 1st decreased by the second is 12 more than twice the 3rd.
ReplyDeleteI agree with anonymous' translation as well. --- That's probably what was meant. I answered a different problem, but I will keep that and people can reference both that way. Thanks for the input!
ReplyDeleteThanks for the example. It really helps.
ReplyDeletethere's nothing wrong with the problem
ReplyDeletehere's my solution...
4x - (x+2) = 12 + 2(x+4)
just use algebra to solve it and you'll get these answers:
x = 22
x+2 = 24
x+4 = 26
let x be the first integer
ReplyDeletex+2 second integer
x+4 third integer
4x-x+2 = 2(x+4) + 12
3x+2 = 2x+8+12
3x+2 = 2x+20
3x-2x = 20-2
x = 18
Checking:
x= 18
x+2= 20
x+4= 22
4x-x+2 = 2(x+4)+12
4(18)-20 = 2(22)+12
72-20 = 44+12
52 = 52
Therefore the numbers are 18, 20 and 22