Find f g for the given function Fx 5x 8 and gx 3x 2 8x6

Find f + g for the given function. F(x) = 5x + 8 and g(x) = -3x - 2 8x-6 -8x + 6 2x + 6 2x-10 Find f -g for the given function. F(x) = 5x + 8 and g(x) = -3x-2

Solution

1)

f(x) = 5x + 8   , g(x) = -3x - 2

f+g means we need to add f(x) and g(x)

f+g = f(x)   + g(x)

       = 5x + 8    + (-3x - 2)

    = 5x + 8 - 3x - 2                      //             +(- x )    = -x              

            = 5x - 3x   + 8 - 2

           = 2x + 6

f -  g

f(x) = 5x + 8

g(x) = -3x - 2

f- g = f(x) - g(x)

             = 5x + 8   - (-3x - 2)

            = 5x + 8 - (-3x) - (-2)

           = 5x + 8 + 3x + 2             //    - (-x) = x         

(whenever -ve sign is before a bracket the signs of the terms    inside bracket gets reversed)

         = 8x + 10