How do you multiply and divide mixed numbers

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove

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

Which of these statements is correct? the system of linear equations 6x - 5y = 8 and 12x - 10y = 16 has no solution. the system of linear equations 7x + 2y = 6 and 14x + 4y = 16 has an infinite number of solutions. the system of linear equations 8x - 3y = 10 and 16x - 6y = 22 has no solution. the system of linear equations 9x + 6y = 14 and 18x + 12y = 26 has an infinite number of solutions.