Let's break down each part of your question step by step.
Part 1: Equivalent Expressions
Expressions to check:
- \(-0.4b + (6b - 5.9a)\)
- \((3.4a - 1.7b) + (2.5a - 3.9b)\)
- \(5.9a - 5.6b\)
- \((2.5a + 1.6b) + (3.4a + 4b)\)
- \((-3.9b + a) + (-1.7b + 4.9a)\)
To simplify each expression:
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Expression 1: \[ -0.4b + 6b - 5.9a = (6b - 0.4b) - 5.9a = 5.6b - 5.9a \]
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Expression 2: \[ (3.4a - 1.7b) + (2.5a - 3.9b) = (3.4a + 2.5a) + (-1.7b - 3.9b) = 5.9a - 5.6b \]
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Expression 3: It is already \(5.9a - 5.6b\).
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Expression 4: \[ (2.5a + 1.6b) + (3.4a + 4b) = (2.5a + 3.4a) + (1.6b + 4b) = 5.9a + 5.6b \]
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Expression 5: \[ (-3.9b + a) + (-1.7b + 4.9a) = (a + 4.9a) + (-3.9b - 1.7b) = 5.9a - 5.6b \]
Equivalent expressions are:
- Expression 1: \(5.6b - 5.9a\)
- Expression 2: \(5.9a - 5.6b\)
- Expression 3: \(5.9a - 5.6b\)
- Expression 5: \(5.9a - 5.6b\)
So, the equivalent expressions are 1, 2, 3, and 5.
Part 2: Expression Equivalent to \(30(1/2x - 2) + 40(3/4y - 4)\)
Simplifying:
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Distributing the constants: \[ 30 \left( \frac{1}{2}x - 2 \right) = 15x - 60 \] \[ 40 \left( \frac{3}{4}y - 4 \right) = 30y - 160 \]
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Combining these gives: \[ 15x - 60 + 30y - 160 = 15x + 30y - 220 \]
So, the expression that is equivalent is 15x + 30y - 220.
Part 3: Value that Fills in The Blank
The equation is \(32 + 72 = ? (4 + 9)\).
First, calculate \(4 + 9\): \[ 4 + 9 = 13 \]
Now calculate \(32 + 72\): \[ 32 + 72 = 104 \]
To find the value that fills in the blank, we need: \[ ? \cdot 13 = 104 \]
Dividing both sides by 13 gives: \[ ? = \frac{104}{13} = 8 \]
Thus the value that fills in the blank is 8.
Summary of Answers
- Equivalent expressions: 1, 2, 3, 5
- Equivalent expression for \(30(1/2x - 2) + 40(3/4y - 4)\): 15x + 30y - 220
- Value that fills in blank: 8