The word per indicates the slope (m) of a linear function, y=mx +b.Using d for x and p for y , the equation representing Ashely's reading is p = 10d. Carly begins on page 40 which represents b, the y intercept of a linear function which indicates an initial amount. So the equation representing Carly's reading is p=8d + 40.
(9+w)w=252 or w(w+9)=252. The quadratic equation applies: w²+9w-252=0=(w+21)(w-12), so w=12, because a negative zero is meaningless. So the dimensions are width=12 in and length=21 in.
