These tiles represent the expression x+4+2x–1.

To simplify the expression \( x + 4 + 2x - 1 \), you can combine like terms:

1. Combine the \( x \) terms: \[ x + 2x = 3x \]

2. Combine the constant terms: \[ 4 - 1 = 3 \]

Putting it all together: \[ x + 4 + 2x - 1 = 3x + 3 \]

So, the equivalent expression is \( 3x + 3 \).