25 /45 = x /3,5

To solve the equation \( \frac{25}{45} = \frac{x}{3.5} \), you can use cross-multiplication. This means multiplying across the equals sign:

\[ 25 \times 3.5 = 45 \times x \]

Calculating \( 25 \times 3.5 \):

\[ 25 \times 3.5 = 87.5 \]

So, we have:

\[ 87.5 = 45x \]

Next, solve for \( x \) by dividing both sides by 45:

\[ x = \frac{87.5}{45} \]

Calculating \( \frac{87.5}{45} \):

\[ x \approx 1.9444 \]

So, the value of \( x \) is approximately \( 1.9444 \).