To determine which expressions are equivalent, let’s simplify each expression step by step.
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First Expression: \[ (-3.9b + a) + (-1.7b + 4.9a) \] Combining like terms: \[ = a + 4.9a + (-3.9b - 1.7b) = 5.9a - 5.6b \]
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Second Expression: \[ (2.5a + 1.6b) + (3.4a + 4b) \] Combining like terms: \[ = 2.5a + 3.4a + 1.6b + 4b = 5.9a + 5.6b \]
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Third Expression: \[ 5.9a - 5.6b \] This is simplified as it stands.
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Fourth Expression: \[ -0.4b + (6b - 5.9a) \] Combining like terms: \[ = -0.4b + 6b - 5.9a = 5.6b - 5.9a \] Note that this can be rearranged to: \[ = -5.9a + 5.6b \]
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Fifth Expression: \[ (3.4a - 1.7b) + (2.5a - 3.9b) \] Combining like terms: \[ = 3.4a + 2.5a - 1.7b - 3.9b = 5.9a - 5.6b \]
Now let’s summarize the results:
- First Expression simplifies to \( 5.9a - 5.6b \)
- Second Expression simplifies to \( 5.9a + 5.6b \)
- Third Expression is \( 5.9a - 5.6b \)
- Fourth Expression simplifies to \( -5.9a + 5.6b \)
- Fifth Expression simplifies to \( 5.9a - 5.6b \)
From the above, the equivalent expressions are:
- First Expression: \( 5.9a - 5.6b \)
- Third Expression: \( 5.9a - 5.6b \)
- Fifth Expression: \( 5.9a - 5.6b \)
Therefore, the three expressions that are equivalent are:
- \( (-3.9b + a) + (-1.7b + 4.9a) \)
- \( 5.9a - 5.6b \)
- \( (3.4a - 1.7b) + (2.5a - 3.9b) \)
Please note that the second expression \( 5.9a + 5.6b \) and the fourth expression \( -5.9a + 5.6b \) are not equivalent to the others.