1. Diketahui f(x)=x²-3 g(x) =x-3 maka (f+g)(x)=….

1. ( f + g ) ( x )
{ ( x2 – 3 ) + ( x – 3 ) } ( x ) = 0
x2 – 3 + x – 3 . x = 0
x2 – 3 + x – 3x = 0
x2 – 3x + x – 3 = 0
x2 – 2x – 3 = 0
( x – 2 ) ( x + 1 ) = 0
x – 2 , x + 1 = 0
x = 2 , x = – 1.

2. ( f + g ) ( x )
{ ( 3×2 – 2x + 3 ) + ( 4×2 – 5x + 2 ) } ( x )
3×2 – 2x + 3 + 4×2 – 5x + 2 . x = 0
3×2 – 2x + 3 + 4×2 – 5x + 2x = 0
3×2 + 4×2 – 2x – 5x + 2x + 3 = 0
7×2 -5x + 3 = 0
7 ( x – 5 ) ( x + 2 ) = 0
7x – 35 , x + 2 = 0
7x = 35 , x = – 2
x = 35/7 = 5.

3. ( f + g ) ( x )
{ ( x2 – 2x + 5 ) + ( x + 5 ) } ( x )
x2 – 2x + 5 + x + 5 . x = 0
x2 – 2x + 5 + x + 5x = 0
x2 – 2x + x + 5x + 5 = 0
x2 + 4x + 5 = 0
( x – 4 ) ( x + 1 ) = 0
x – 4 , x + 1 = 0
x = 4 , x = – 1.

4. ( f + g ) ( x )
{ ( 5×2 – 2x + 5 ) + ( 2×2 – 3 ) } ( x )
5×2 – 2x + 5 + 2×2 – 3 . x = 0
5×2 – 2x + 5 + 2×2 – 3x = 0
5×2 + 2×2 – 2x – 3x + 5 = 0
7×2 – 5x + 5 = 0
7 ( x – 5 ) ( x + 5 ) = 0
7x – 35 , x + 5 = 0
7x = 35 , x = – 5
x = 35 / 7 = 5.

5. ( f + g ) ( x )
{ ( x2 + 3x – 1 ) + ( 4×2 – 3 ) } ( x )
x2 + 3x – 1 + 4×2 – 3 . x = 0
x2 + 3x – 1 + 4×2 – 3x = 0
x2 + 4×2 + 3x – 3x – 1 = 0
5×2 + x – 1 = 0
5 ( x – 1 ) ( x + 1 ) = 0
5x – 5 , x + 1 = 0
5x = 5 , x = – 1
x = 5 / 5 = 1.