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

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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!