(450-300)•х

To simplify the expression \((450 - 300) \cdot x\):

1. First, calculate \(450 - 300\): \[ 450 - 300 = 150 \]

2. Then, multiply by \(x\): \[ 150 \cdot x = 150x \]

So, \((450 - 300) \cdot x = 150x\).