How do you find the value of two numbers if their sum is 12 and their difference is 4?

Question

1599 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-01-30T21:43:37

#a = 8#.
#b = 4.#

Let #a# and #b# be the two numbers we are looking for. We know that their sum is 12, and that their difference is 4. Then, this means that:

#a + b = 12# (1);

#a - b = 4# (2).

If we sum equations (1) and (2):

#a + b + a - b = 12 + 4#;

#2a = 16#;

#a = 8#.

Now we can take this value for #a# and place it in either equations (1) or (2); which will yield the same result for #b#:

#8 + b = 12#;

#b = 4.#

Hope it helped you!