Question

If f(x) = 2x^2+1 and g(x) =x^2-7 find (f+g)(x)

Answer 1

F(x) + g(x) = [2x^2 + 1] + [x^2 – 7]

≈ 3x^2 – 6

Hence (f + g)(x) = 3x^2 – 6

Answer 2

Answer:f=−

​7

​

​x

​2

​​ +1−2g−x

​​  

Step-by-step explanation:

1 Subtract {x}^{2}x

​2

​​  from both sides.

2{x}^{2}+1-g-x-{x}^{2}=-7f+g2x

​2

​​ +1−g−x−x

​2

​​ =−7f+g

2 Simplify  2{x}^{2}+1-g-x-{x}^{2}2x

​2

​​ +1−g−x−x

​2

​​   to  {x}^{2}+1-g-xx

​2

​​ +1−g−x.

{x}^{2}+1-g-x=-7f+gx

​2

​​ +1−g−x=−7f+g

3 Subtract gg from both sides.

{x}^{2}+1-g-x-g=-7fx

​2

​​ +1−g−x−g=−7f

4 Simplify  {x}^{2}+1-g-x-gx

​2

​​ +1−g−x−g  to  {x}^{2}+1-2g-xx

​2

​​ +1−2g−x.

{x}^{2}+1-2g-x=-7fx

​2

​​ +1−2g−x=−7f

5 Divide both sides by -7−7.

-\frac{{x}^{2}+1-2g-x}{7}=f−

​7

​

​x

​2

​​ +1−2g−x

​​ =f

6 Switch sides.

f=-\frac{{x}^{2}+1-2g-x}{7}f=−

​7

​

​x

​2

​​ +1−2g−x

​​