solve by setting up a linear system
2007-07-30 05:07:11 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Hi,
x + x + 5 = -31
2x + 5 = -31
2x = -36
x = -18
x + 5 = -13
-18 and -13 are the numbers
2007-07-30 05:09:24 · answer #1 · answered by Pi R Squared 7 · 2⤊ 0⤋
You have two numbers. Call them x and y. The first sentence says one is 5 bigger than the other so you can write and equation: x+5=y. The other says that adding them together you get -31 so x+y = -31. Since the first equation is solved for y you can substitute it into the second to get:
x+x+5 = -31. This is simplified to 2x=-36. Therefore x = -18. Put this into the first equation to get -18+5 = y and you find out that y = -13.
2007-07-30 05:12:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
THe numbers are -18 & -13.
2007-07-30 05:11:00 · answer #3 · answered by A M Frantz 7 · 0⤊ 0⤋
Let x = 1st no., x + 5 = 2nd no.
x + x + 5 = - 31
2x = - 31 - 5
2x = - 36
x = - 36 / 2
x = - 18
Answer: 1st no. is -18, 2nd is - 13 (- 18 + 5), the sum is - 31.
Proof:
(- 18) + (- 15) = - 31
- 18 - 15 = - 31
- 31 = - 31
2007-08-03 04:56:34 · answer #4 · answered by Jun Agruda 7 · 2⤊ 0⤋
-13 + -18 = -31
2007-07-30 05:10:54 · answer #5 · answered by Steve C 7 · 0⤊ 0⤋
13+18=31, so -13+-18=-31
2007-07-30 05:11:23 · answer #6 · answered by nita5267 6 · 0⤊ 0⤋
Let 1st number - X, 2nd - X+5, then
x+x+5=-31
2x+5=-31
2x=-36
x=-18, (the 1st number)
-18+5=-13 , (the 2nd number)
2007-07-30 05:13:13 · answer #7 · answered by Len4ik 2 · 0⤊ 0⤋
x = y + 5
x + y = -31
__________
I advise you to use the substitution method to solve this system.
Since the x-term is already isolated in the first equation, use its equivalent expression to substitute into the other equation, and then solve for y.
Okay, here goes....
(y + 5) + y = -31
2y + 5 = -31
2y = -36
y = -18
Now substitute this value into EITHER one of the original equations. It doesn't matter which one.
I choose the first one i wrote, x = y + 5.
x = -18 + 5
x = -13
Therefore the two numbers are -18 and -13.
Hope this helps! :-)
2007-07-30 05:08:46 · answer #8 · answered by apodosis 2 · 0⤊ 1⤋
let one number be x and another number be y then,
x=y+5.........equation 1
the sum of one number and another number is -31
x+y=-31..........equation 2
now equate equation 1 into equation 2
(y+5)+y=-31
2y+5=-31
2y=-31-5
2y=-36
y= -18
put y=-18 in equation 1
x= -18+5
x= -13.
2007-07-30 05:24:15 · answer #9 · answered by Emperor 3 · 0⤊ 0⤋
-13, -18
Ok, I was a little too slow. It's just like the answer above this one.
;)
2007-07-30 05:09:44 · answer #10 · answered by Anonymous · 0⤊ 0⤋