The graph of f(x) = 2x + 4 shifts six units to the right when it is replaced with the graph of f(x) = 2x - k. What is the value of k?
2
4
6
10

Question

The graph of f(x) = 2x + 4 shifts six units to the right when it is replaced with the graph of f(x) = 2x - k. What is the value of k?
 2
 4
 6
 10

welshfella · Answer

first lets find where the graph f(x) = 2x + 4 cuts the x axis
2x + 4 = 0    where  it cuts x-axis so
2x + 4 = 0
2x = -4
x = -2

reginabusch · Answer

I figured it out, thank you so much!

welshfella · Answer

So the new line moves 6 to the right therefore it cuts the xx-axis at x = 4
so we have

0 = 2(4) - k

solve for k

welshfella · Answer

ok but none of the choices are correct 
k = 8

reginabusch · Answer

hmm I got 6 and it was correct. I guess theres a typo in the question. Thank you anyways

welshfella · Answer

yes

welshfella · Answer

if k = 6 then the lines moves 5 units to the right