Question

the sum of 2 numbers is 1000 and the difference is 998. what are the 2 numbers

Answer 1

If we let one of the numbers be 'x' and another be 'y' do you think you can write the two pieces of information as algebraic expressions?

Answer 2

no...buts the question is an algebraic one...

Answer 3

Okay, I'll help you with the first one.

The first statement says that the two numbers add up to 1000.
We can write this as:

x + y = 1000

Where x and y are the two numbers. Do you think you can do the difference one?

Answer 4

yes...then the second statement says x-y=998

Answer 5

now what are x & y

Answer 6

There are a few ways to do this. This site has some information on solving these kind of equations. http://www.allaboutcircuits.com/vol_5/chpt_4/11.html

I will use the substitution method.

(1) x + y = 1000
(2) x - y = 998

Rearrange 2 to get 'y' as the subject.
x - y = 998
y = -998 + x

Now substitute this new 'y' into the original (1).
x + (-998 + x) = 1000
x -998 + x = 1000
2x = 1998
x = 999

Now, to find 'y', substitute this new x either (1) or (2).
x - y = 998
999 - y = 998
y = 999 - 998
y = 1

Therefore the two numbers are 999 and 1.

Answer 7

Does that help? :)

Answer 8

super...

Answer 9

thank you

Answer 10

You're welome