Question

1/4 (5x - 16) - 1/2 (3rd - 8) при x=2 2/5 , y = 6

Answer 1

$\frac{1}{4} (5x - 16) - \frac{1}{2} (3y - 8) = \\ \frac{5}{4} x - 4 - \frac{3}{2} y + 4 = \\ \frac{5}{4}x - \frac{3}{2} y = \frac{5}{4} \times 2 \frac{2}{5} - \frac{3}{2} \times 6 = \\ \frac{5}{4} \times \frac{12}{5} - \frac{3}{2} \times \frac{6}{1} = \\ 3 - 9 = - 6$

Answer 2

To evaluate the expression $\frac{1}{4}(5x - 16) - \frac{1}{2}(3x - 8)$ with the given values $x = \frac{2}{5}$ and $y = 6$, we'll substitute the value of $x$ into the expression and perform the calculations.

Step 1: Substitute the value of $x$: $\frac{1}{4}(5 \cdot \frac{2}{5} - 16) - \frac{1}{2}(3 \cdot \frac{2}{5} - 8)$

Step 2: Simplify the expressions within the parentheses: $\frac{1}{4}(2 - 16) - \frac{1}{2}(\frac{6}{5} - 8)$

Step 3: Perform the arithmetic operations inside the parentheses: $\frac{1}{4}(-14) - \frac{1}{2}(\frac{6}{5} - \frac{40}{5})$

Step 4: Continue simplifying: $\frac{-14}{4} - \frac{1}{2}(\frac{-34}{5})$

Step 5: Calculate the fractions: $\frac{-14}{4} - \frac{-34}{10}$

Step 6: Convert the fractions to have a common denominator: $\frac{-14}{4} + \frac{34}{10}$

Step 7: Simplify the expression further: $\frac{-7}{2} + \frac{17}{5}$

Step 8: To add these fractions, they need to have a common denominator. The common denominator is $2 \times 5 = 10$: $\frac{-35}{10} + \frac{34}{10}$

Step 9: Add the fractions together: $\frac{-1}{10}$

So, the value of the expression when $x = \frac{2}{5}$ and $y = 6$ is $-\frac{1}{10}$.