Can anybody me show my work for these have the correct answer just no work to prove

1.given f(x) = x2 + 2x, find f(a _ 3)
a: a^2-4a+3

2. if f(x0=x/x-3 and g(x)=2x-1, find (f-g)(x)
a: -2x^2+8x-3/x-3

3. if f(x)=x^2+1 and g(x)=1/x, find [f*g](x)
a: 1/x^2 +1

4. which equation best represents a line perpendicular to the graph of x+3y=9?
a: y=3x-1

5. which of the following describes the graphs of 2x+5y=9 and 10x=4y+18?
a: perpendicular

6. write the standard form of an equation of the line parallel to the graph of x-2y-6=0 and passing through a(

1)
f(x) = x^2 + 2x
So lets replace all the x parts with (a-3) f(a-3) = (a-3)^2 + 2(a-3)
and the rest is just expanding it out from there.
A: a^2-4a+3

2. If f(x0=x/x-3 and g(x)=2x-1, find (f-g)(x)
A: -2x^2+8x-3/x-3

3. If f(x)=x^2+1 and g(x)=1/x, find [f*g](x)
A:1/x^2 +1

4. Which equation best represents a line perpendicular to the graph of x+3y=9?
A:y=3x-1

5. Which of the following describes the graphs of 2x+5y=9 and 10x=4y+18?
A: perpendicular

6. Write the standard form of an equation of the line parallel to the graph of x-2y-6=0 and passing through A(-3,2)
 A: x-2y+7=0

Yes i also think it is b