Question

f(x, y) = 4x + 7y - 6, please find the value of f(5,-5).

Answer 1

f(x, y) = 4x + 7y - 6

substitute x=5 and y=-5

f(5,-5) = 4(5) + 7(-5) - 6

f(5,-5) =20-35-6

        = -15-6

        =-21