Use the number line below, where RS = 5y +5, ST = 3y +6, and RT = 12y - 21. a. What is the value of y? b. Find RS, ST, and RT. a. What is the value of y? y = (Type an integer or a decimal.)

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