To determine which expressions are equivalent, we will simplify each expression.
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Expression 1: \((-3.9b + a) + (-1.7b + 4.9a)\)
- Combine like terms: \[ a + 4.9a - 3.9b - 1.7b = (1 + 4.9)a + (-3.9 - 1.7)b = 5.9a - 5.6b \]
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Expression 2: \(5.9a - 5.6b\)
- This is already simplified.
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Expression 3: \((2.5a + 1.6b) + (3.4a + 4b)\)
- Combine like terms: \[ 2.5a + 3.4a + 1.6b + 4b = (2.5 + 3.4)a + (1.6 + 4)b = 5.9a + 5.6b \]
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Expression 4: \((3.4a - 1.7b) + (2.5a - 3.9b)\)
- Combine like terms: \[ 3.4a + 2.5a - 1.7b - 3.9b = (3.4 + 2.5)a + (-1.7 - 3.9)b = 5.9a - 5.6b \]
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Expression 5: \(-0.4b + (6b - 5.9a)\)
- Simplify it: \[ -0.4b + 6b - 5.9a = (6 - 0.4)b - 5.9a = 5.6b - 5.9a \]
- Rearranging gives: \[ -5.9a + 5.6b \]
Now let's check for equivalency:
- Expression 1 simplifies to \(5.9a - 5.6b\).
- Expression 2 is \(5.9a - 5.6b\).
- Expression 3 simplifies to \(5.9a + 5.6b\).
- Expression 4 simplifies to \(5.9a - 5.6b\).
- Expression 5 simplifies to \(-5.9a + 5.6b\) (which is equivalent to \(5.6b - 5.9a\), i.e., the negative).
The expressions that are equivalent are:
- Expression 1: \(5.9a - 5.6b\)
- Expression 2: \(5.9a - 5.6b\)
- Expression 4: \(5.9a - 5.6b\)
Thus, the three that apply are:
- \((-3.9b + a) + (-1.7b + 4.9a)\)
- \(5.9a - 5.6b\)
- \((3.4a - 1.7b) + (2.5a - 3.9b)\)