2007-07-06 07:17:09 · 19 answers · asked by Renee S 1 in Science & Mathematics ➔ Mathematics
I don't like doing homework but it's:
18 and 11
2007-07-06 07:19:27 · answer #1 · answered by Sam R 2 · 1⤊ 1⤋
Let one of the numbers be x
Let the other number be y
x+y=29
x-y=7
Two ways to solve this:
A) By addition method
x+y=29
x- y=7
------------
2x = 36, x= 18
Y
Use either equation to find y, knowing x = 18
18+y=29, y=29 - 18, y=11
B) Substitution Method
x + y = 29
x - y = 7
Find y in terms of x or x in terms of y, whichever way is easiest. I'll use equation 1 to say y = 29 - x. This gets substituted into the second equation, to give us
x - (29-X) = 7
X - 29 +X =7
2X - 29 = 7
2X = 7 + 29
2x = 36
x = 18
Substitute as was done in the first method, to again get y = 11
Check the answer
18+11=29
18-11=7
Hope this helps
2007-07-06 14:33:58 · answer #2 · answered by Grampedo 7 · 0⤊ 0⤋
18 and 11
2007-07-09 12:54:39 · answer #3 · answered by cutest pooky 3 · 0⤊ 0⤋
18 and 11
2007-07-08 00:22:19 · answer #4 · answered by ? 5 · 0⤊ 0⤋
call the 1st number is x, 2nd number is y.
We'll have: x+y=29 and x-y=7
=>2x=36 and x-y=7
=>x=18 and x-y=7
=>x=18 and 18-y=7
=>x=18 and y=11
2007-07-06 14:28:26 · answer #5 · answered by God_Of_War 2 · 0⤊ 0⤋
18 and 11
2007-07-06 14:21:10 · answer #6 · answered by Sam 6 · 0⤊ 1⤋
Let x = 1st no.; y = 2nd no.
1st equation:
x + y = 29
y = 29 - x
2nd equation:
x - y = 7
x - 7 = y
3rd equation:
29 - x = x - 7
29 + 7 = x + x
22 = 2x
22 / 2 = x
x = 11
4th equation:
y = 29 - x
y = 29 - 11
y = 18
Answer x = 11; y = 18
1st proof:
x + y = 29
11 + 18 = 29
2nd proof:
y - x = 7
18 - 11 = 7
2007-07-10 12:20:35 · answer #7 · answered by Jun Agruda 7 · 2⤊ 0⤋
Let x represent the first #
Let y represent the second #
Therefore, x+y=29
x-y= 7
either by elimination or substitution, you can solve for one of the variables.....
isolate y in the first equation...... y=29 - x
substitute that into the second equation......
x-(29-x)=7
x-29+x=7
2x=7+29
2x=36
x=36/2
x=18
Therefore, if one number is 18 the other must be 11.
11 and 18 are the numbers
2007-07-06 14:27:35 · answer #8 · answered by A G 1 · 0⤊ 0⤋
18 and 11
If x+y=29 and x-y=7
then 29-y=x from the first equation, so substituting into the second gives us (29-y)-y=7 so 29-2y=7
so, -2y=-22 and y=11
Then, knowing that x+11=29, so x must equal 18
2007-07-06 14:20:48 · answer #9 · answered by Mr. me 2 · 0⤊ 0⤋
11 & 18
2007-07-06 14:19:58 · answer #10 · answered by MARK J 2 · 0⤊ 1⤋
Yes the numbers are correct. 18 and 11 is the right answer.
But, everybody has done x-y =7
How do you know x>y.....?
It can also be y>x....then, y-x =7.........even then, the answers would be the same ( only values will interchange w.r.t unknown variable). But when a difference is given but, no condition is specified, we take mod of (x-y) i.e. two conditions into account. That's the correct approach.........remember.
2007-07-06 14:26:24 · answer #11 · answered by Shobiz 3 · 0⤊ 0⤋