An architect is designing a house on an empty plot. The area of the plot can be modeled by the polynomial ${3x^{4}+14x^{2}-6.5x}$, and the area of the house’s base can be modeled by ${5x^{3}-6.5x+50}$. The rest of the plot is the yard. What’s the yard’s area? The area of the yard can be modeled by the polynomial .