Given #f(x)=3x^2+4x-5# and #g(x)=2x+9#, how do you find #f(x)+g(x)#, #f(x)-g(x)# and #f(x)*g(x)# and #(f/g)(x)#?
1 Answer
Jun 22, 2018
We have:
# f(x) = 3x^2+4x-5 # and#g(x)=2x+9#
So then:
# (f+g)(x) = f(x)+g(x) #
# " " = (3x^2+4x-5)+(2x+9) #
# " " = 3x^2+6x+4 #
# (f-g)(x) = f(x)-g(x) #
# " " = (3x^2+4x-5)-(2x+9) #
# " " = 3x^2+2x-14 #
# (fg)(x) \ \ \ \ \ = f(x) * g(x) #
# " " = (3x^2+4x-5)(2x+9) #
# " " = 2x(3x^2+4x-5) + 9(3x^2+4x-5) #
# " " = 6x^3+8x^2-10x + 27x^2+36x-45 #
# " " = 6x^3+35x^2+26x -45 #
# (f/g)(x) \ \ = f(x) / g(x) #
# " " = (3x^2+4x-5)/(2x+9) #
