If #f(x) = 5x^2+6# and #g(x) = -3x+3#, what is #(f-g)(-3)#?

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Answer 1 · 2018-03-02T15:11:51

#39#

Remember that #(f-g)(x)=f(x)-g(x)#.

Here, #f(x)=5x^2+6# and #g(x)=-3x+3#.

#f(x)-g(x)=h(x)=5x^2+6-(-3x+3)#

#h(x)=5x^2+6+3x-3#

#h(x)=(f-g)(x)=5x^2+3x+3#

So, we now have #(f-g)(x)#. Next, we can do:

#(f-g)(-3)=h(-3)=5(-3)^2+3(-3)+3#

#(f-g)(-3)=39#

Our answer.

Answer 2 · 2018-03-02T15:13:08

#(f-g)(-3)=39#

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

#color(white)((f-g)(x))=5x^2+6-(-3x+3)#

#color(white)((f-g)(x))=5x^2+6+3x-3#

#color(white)((f-g)(x))=5x^2+3x+3#

.#"to evaluate "(f-g)(-3)" substitute x = - 3 into "(f-g)(x)#

#(f-g)(color(red)(-3))=(5xx(color(red)(-3))^2)+(3xxcolor(red)(-3))+3#

#color(white)(xxxxxxxx)=(5xx9)-9+3#

#color(white)(xxxxxxxx)=45-9+3=39#

Answer 3 · 2018-03-02T15:13:30

39

we have got f(x)=#5x^2+6#
we have to find f-g..so lets find it f-g=#5x^2+6+3x-3#= #5x^2+3x+3#

now put x=-3 in above equation
we ll get result
thnx!!!