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The sum of two numbers is 3. Their difference is -5. What are the two numbers?

User Moncef
by
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1 Answer

4 votes
x + y = 3
x - y = -5

We can solve using substitution
x + y = 3
subtract x to isolate y
y = 3 - x
substitute it into the second expression
x - y = -5
x - 3 + x = -5
combine like terms
2x - 3 = -5
add 3 to both sides
2x = -2
divide both sides by 2
x = -1

now to find y

x + y = 3
-1 + y = 3
add 1 to both sides
y = 4

User Brian Spiering
by
7.8k points

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