what is the sum of a pair of numbers that add to 13 and subtracts to 7

Answer 1

Answer 2

If a pair of numbers adds to 13, their sum is 13. If you want to know what the two numbers are, then:

x + y = 13

x - y = 7

Add the two equations together:

x + y = 13

x - y = 7

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2x + 0 = 20

2x = 20

x = 10

To find y, plug 10 into either of the equations above in place of x then solve for y.