Can you help me with this math question?

set up:

x+y=x-y+17

to find y

x+y=x-y+17

= y=-y+17

= 2y=17

= y=17/2=8.5

to find x

(8.5)+17=x

= 25.5=x=51/2

check

25.5+8.5=25.5-8.5+17

34=34

Let the two numbers be x and y, with x >= y. Then the given information says that

x + y = 17 + x - y.

Note that we can cancel out the x's, so this equation is equivalent to the equation

y = 17 - y.

We have a problem; this equation gives us no information about x, so we can't determine what x is. Are you sure you copied the entire problem? We can still solve for y:

y = 17 - y

2y = 17

y = 17/2 = 8.5.

We conclude that one of the numbers is 8.5, and the other could be any number greater than or equal to 8.5.

x + y = x - y + 17

2y = 17

y = 8.5

Any differential of 17 (x +/- 8.5) will give you a value for x except for 17, 0

(x would = 8.5) start at 18, 1

if x + 8.5 = 18

then x - 8.5 = 1 (add equations)

2x = 19

x = 9.5

if x + 8.5 = 20

then x - 8.5 = 3 (add equations)

2x = 23

x = 11.5

I have an addition to your first answer: Since you know that y=8,5, then x has to be 17 more than that or 25.5.

Proof by substitution:

25.5 + 8.5 = 17 + 25.5 - 8.5

34 = 42.5 - 8.5

34 = 34