2400:(k+300)=40

To solve the equation \( \frac{2400}{k + 300} = 40 \), follow these steps:

1. Multiply both sides by \( k + 300 \) to eliminate the denominator: \[ 2400 = 40(k + 300) \]

2. Distribute the 40 on the right side: \[ 2400 = 40k + 12000 \]

3. Subtract 12000 from both sides: \[ 2400 - 12000 = 40k \] \[ -9600 = 40k \]

4. Divide both sides by 40: \[ k = \frac{-9600}{40} \] \[ k = -240 \]

So, the solution is \( k = -240 \).