678-378-x=50

To solve the equation \( 678 - 378 - x = 50 \), follow these steps:

1. Combine like terms on the left side: \[ 678 - 378 = 300 \] So, the equation becomes: \[ 300 - x = 50 \]

2. Next, isolate \( x \) by subtracting 300 from both sides: \[ -x = 50 - 300 \] \[ -x = -250 \]

3. Multiply both sides by -1 to solve for \( x \): \[ x = 250 \]

Thus, the solution is \( x = 250 \).