13+3,2x+0,4x=40

To solve the equation \( 13 + 3.2x + 0.4x = 40 \), follow these steps:

1. Combine like terms on the left side of the equation: \[ 3.2x + 0.4x = 3.6x \] So the equation now reads: \[ 13 + 3.6x = 40 \]

2. Next, isolate \( x \) by first subtracting 13 from both sides: \[ 3.6x = 40 - 13 \] \[ 3.6x = 27 \]

3. Finally, divide both sides by 3.6 to solve for \( x \): \[ x = \frac{27}{3.6} \]

4. Simplifying \( \frac{27}{3.6} \): \[ x = 7.5 \]

Thus, the solution is: \[ x = 7.5 \]