Queation that has no answer, unless someone finds one...?

Question

Best answer
142 answers

Math question help?

w+x+y+z=81

5x=w
5y=x
2y=z

what does x equal???


I got 14.464 and thats wrong apparently, the answer is supposed to be 5. how does that work?

If you check your work, only x=5 works. It's so confusing.

it was from another question, i tried it but it didn't work in the equation, is the equation wrong, am i not supposed to solve it mathematiclly

http://answers.yahoo.com/question/index;_ylt=AlC5UMQBWLxGZUKaRFFhT.vsy6IX?qid=20070117132021AAOBzwO&show=7#profile-info-f34166a9b2bb1889eba9c4a9a710f5eaaa

Answer 1

You've stuffed up when you were getting these formulas.
It should be
w + x + y + z = 81
x = 5w
y = 5x
z = 2y

then you get 5 for x.
because x is the son who is 5 times older than the daughter who is w which makes the equation x = 5w
also the wife who is y is 5 times older than the son (x) so the equation is y = 5x.
Try this.

Answer 2

w + x + y + z = 81

Strategy: Get everything to x:

5x + x + x/5 + z = 81 Note: Since 5y = x, then x/5 = y.

2y = z
2(x/5) = z

5x + x + x/5 + 2(x/5) = 81

Next, clean out fractions by multiplying both sides by 5.
25x + 5x + x + 2x = 5*81 = 405.
33x = 405
x = 405/33 = 12.2727

Well, that is not 5, so lets check the answer
w = 5x = 61.3636
y = x/5 = 2.4545
z=2y = 4.9090
x=12.2727
61.3636 + 12.2727 + 2.4545 + 4.9090 = 80.9998 or 81.

To work out exactly, you would need
x = 405 / 33 or 12 9/33. 12.2727 is close, but not exactly 12 9/33.

Answer 3

Substitute x=5 on the left hand side and you get 33.
So x=5 is wrong.

Given
w+x+y+z=81 .....(a)

5x=w .....(b)
5y=x .....(c)
2y=z .....(d)

From (c)
y = x/5 .....(i)

From (d) and (i)
z = 2x/5 .....(ii)

Substitute (b), (i) and (ii) into (a).
5x + x + x/5 + 2x/5 = 81

Simplify the left hand side.
(25x + 5x + x + 2x)/5 =81
33x/5 = 81

Multiply both sides by 5/33.
x = 81 * 5/33
x = 405/33 = 12 9/33
x = 12 3/11 (Twelve and three elevenths)

Substituting x=12 3/11 on left hand side gives
61 4/11 + 12 3/11 + 2 5/11 + 4 10/11
= 79 + 22/11
= 79 + 2
= 81 = right hand side

Answer 4

The question must be wrong because 5 doesn't work. But neither does 14.464. I calculated x = 12.27.

w + x + y + z = 81
5x + x + y + 2y = 81
6x + 3y = 81
6x + (3/5) 5y = 81
6x + (3/5)x = 81
6.6x = 81

x = 12.27

Check the answer:

5x = w ; w = 61.4
5y = x ; y = 2.45
2y = z ; z = 4.91

w + x + y + z = 61.4 + 12.27 + 2.45 + 4.91 = 81. QED

Answer 5

w+x+y+z = 81

Using your terms: w = 5x

5x + x +y +z = 81

6x +y + z = 81 (x = 5y)

30y +y +z = 81

31y +z = 81 (z = 2y)

33y = 81

y = 81/33

y = 27/11

Answer 6

5 didnt work for me either