Jamie ordered 200 business cards and paid 23$. she ordered 500 business cards a few months later and paid 35$. write and solve a linear equation to find the cost to order 700 business cards

Find the directions in which the function increases and decreases most rapidly at upper p 0p0. then find the derivatives of the function in these directions. f(x, y)equals=x squared plus xy plus y squaredx2+xy+y2, upper p 0p0left parenthesis 1 comma negative 4 right parenthesis