I believe the area is 37.5
We first simplify the equation: 0.1x = 0.2x + 0.2 * 2, then we move the left side 0.1x to the right side, the 0.2 * 2 to the right side and we have -0.4 = 0.2x - 0.1x, then we have -0.4 = 0.1x, so we have x = -4
Answer:
40 cm equals 400 millimeters
I hope this helps you