This is a simple question where students need to use BIDMAS to solve the equation. The easiest method is to seperate the two sides and solve individually, then combine. Firstly, 3(x+5) multiplies out to give 3x+15. The second part 4(2x+1) multiplied out gives 8x+4. Combining both sides gives (3x+15)-(8x+4). From here, it's important to remember that if there is a minus in front of a bracket, everything inside the bracket has to be taken away. This leads us to the final answer of -5x+11.