To solve the first expression \( 60\left(\frac{1}{4}x - 2\right) + 20\left(\frac{3}{4}y - 4\right) \):
-
Distribute in both parts: \[ 60\left(\frac{1}{4}x\right) - 60 \cdot 2 + 20\left(\frac{3}{4}y\right) - 20 \cdot 4 \] \[ = 15x - 120 + 15y - 80 \]
-
Combine like terms: \[ = 15x + 15y - 200 \]
Thus, the equivalent expression is: \[ \boxed{15x + 15y - 200} \]
For the second part, we analyze which of the given expressions are equivalent after simplification.
-
First expression: \[ -0.4b + (6b - 9.5a) = -0.4b + 6b - 9.5a = (6 - 0.4)b - 9.5a = 5.6b - 9.5a \]
-
Second expression: \[ (-9.3b + a) + (-7.1b + 8.5a) = -9.3b + a - 7.1b + 8.5a = (-9.3 - 7.1)b + (1 + 8.5)a = -16.4b + 9.5a \]
-
Third expression: \[ (5.2a + 6.1b) + (4.3a + 4b) = 5.2a + 6.1b + 4.3a + 4b = (5.2 + 4.3)a + (6.1 + 4)b = 9.5a + 10.1b \]
-
Fourth expression: \[ (4.3a - 7.1b) + (5.2a - 9.3b) = 4.3a - 7.1b + 5.2a - 9.3b = (4.3 + 5.2)a + (-7.1 - 9.3)b = 9.5a - 16.4b \]
-
Fifth expression: \[ 9.5a - 16.4b \text{ (already simplified)} \]
Therefore, the equivalent expressions are:
- \( -9.3b + a + -7.1b + 8.5a \) (simplifies to \( -16.4b + 9.5a \))
- \( (4.3a - 7.1b) + (5.2a - 9.3b) \) (also simplifies to \( 9.5a - 16.4b \))
- \( 9.5a - 16.4b \) (is equal itself)
So the checked equivalent expressions are:
- \( -9.3b + a + -7.1b + 8.5a \)
- \( (4.3a - 7.1b) + (5.2a - 9.3b) \)
- \( 9.5a - 16.4b \)
Check the three that apply.