For the linear equation #y=2x+4#, if #x# increases by 1 point, how much will #y# increase?

1 Answer
Jul 23, 2016

#Y# will increase by #2#.

Explanation:

graph{y=2x+4 [-8.71, 16.6, 0.49, 13.13]}

The graph above is the graph to the equation #y=2x+4#.

To solve this, I grabbed a random coordinate from the graph. The coordinates were #(1,6)#. I plugged them into the equation.

#6=2(1)+4#

Great! We know the equation works fine. But the question is what will happen to #y# if #x# increased by #1#. So what did I do? I increased #x# by #1# and kept the #y# as a variable so I could solve for it:

#y=2(2)+4#

#y=4+4#

#y=8#

Now let's check our work. Find the #2# on the x-axis and go up until the line runs in the corner of a square. And where could that be? On the number #8# on the y-axis! When #x# was #1#, #y# was #6#. When #x# was 2, #y# was #8#!

When #x# increased by #1#, #y# increased by #2#!