$\"\"$ $\"\"$

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The original weight plus the additional gain is 160.

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$\"\"$

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The equation represents the situation is $\"\"$ $\"\"$

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According to Subtraction property of equality: if $\"\"$ , then $\"\"$ .

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$\"\"$ (Subtract 155 from each side).

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$\"\"$ (Apply commutative property of addition: $\"\"$ )

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$\"\"$ (Apply additive inverse property: $\"\"$ )

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$\"\"$ (Apply additive identity property: $\"\"$ )

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$\"\"$ (Subtract: $\"\"$ )

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$\"\"$

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Check:

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To check the solution, substitute $\"\"$ in original equation.

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$ (Add: $\"\"$ )

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Compare the values, the equation is true. The solution is $\"\"$ .

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$\"\"$

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Darius needs to gain 5 pounds.