Answer:
we have
f(x)=x-6f(x)=x−6 -----> equation A
This is a linear equation with slope m=1m=1 and a y-intercept equal to -6−6
g(x)=x+6g(x)=x+6 -----> equation B
This is a linear equation with slope m=1m=1 and a y-intercept equal to 66
The function f(x) and g(x) are parallel lines
we know that
h(x)=f(x)+g(x)h(x)=f(x)+g(x)
Substitute
h(x)=x-6+x+6h(x)=x−6+x+6
h(x)=2xh(x)=2x
This is a linear equation with slope m=2m=2 that passes through the origin ( represent a direct variation)
Using a graphing tool
see the attached figure