y=x+4 and y=4x+1?

Question

it says solve by graphing. Check your solution..well I know I gotta do the graphing part..but someone help me on showing the work plz

Answer 1

Graph, means you must do this on graph paper!:

y=x+4 means that we have a line with a y intercept at 4 and a slope of 1.

y = 4x+1 means that we have a line with a y intercept at 1 and a slope of 4.

Draw the two lines and where they cross one another is the solution.

Check you work, graphically, typically means after finding that point, plug in the value for your graphed x and see if both solutions come up with the same y value.

Say the solution is x = 1 (the x value where both lines cross, and of course you'll demonstrate this graphically)

Plug in the x value into the first line
y = 1 + 4 = 5

Plug the x value into the second line
y = 4(1) + 1 = 5

Since they check, you know the solution is (1,5)

Answer 2

Here's how you check by doing it by hand:

You know that Y is equal to both "x+4" and "4x+1". Set them equal to each other:

x+4 = 4x+1

Move the X variables on one side, and the numbers on the other. You may end up with "-3x=-3" or "3=3x". It depends on how you balance the equation.

By dividing 3 or -3 to get x by itself, you get "x=1". This means that the x-coordinate of the intersection is at 1.

Plug this x value in either "y=x+4" or "y="4x+1" to get the y value. They should both come out the same.

y=x+4
y=(1)+4
y=5
Same idea with the other.

Therefore, your Y coordinate is 5. So, the lines y=x+4 and y=4x+1 intersect at this common point, (1,5).

Answer 3

even if you graph this it still doesnt make sense.. unless it wants you to show to lines..