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

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The given equation is $\"\"$ .

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$\"\"$ (distribute 7)

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$\"\"$ (Multiply: $\"\"$ )

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$\"\"$ (distribute 2)

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$\"\"$ (Multiply: $\"\"$ )

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$\"\"$ (Apply commutative property of addition: a+b=b+a)

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

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According to subtraction property of equality: Subtract 4t from each side.

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$\"\"$

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$\"\"$ (Apply commutative property of addition: a+b=b+a)

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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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According to addition property of equality: If a = b then a + c = b + c.

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$\"\"$ (Add 21 to each side)

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

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

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

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$\"\"$ (Divide each side by 3)

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$\"\"$ (Cancel common terms) $\"\"$

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Verify:

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

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

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

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$\"\"$ (Multiply: $\"\"$ )

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

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

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The value of t is $\"\"$ .

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