Pls help 25 only and brainlist

Answer:
2x+2
Step-by-step explanation:
Perimeter = 2 * width + 2 * length
12x+10 = 2(4x+3) + 2 * width
12x+10 = 8x + 6 + 2w
4x+4 = 2w
2x+2 = w