The sum of 4 times a girls age and 7 times a boys age is 169. the boy is one year older than twice the age of the girl. find out how old they will be in ten years

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