# algebra

posted by
**dan**
.

solve the system by graphing

x+y=4

y=2x+1

I think these are the kind that you take equation #1 and rewrite it

as y = -x + 4 and do the table for it plot the dots and connect the line for it. then take equation #2 y= 2x+ 1 do the table and do the same and if the lines cross if it has an intersection it will have one solution and plot the point where it intersects and that will be your answer but make sure to write out the answer as a point for example (x , y ). If the lines are parallel to each other I believe that is no solution. And if the lines lie on the same line then its a i can't remember the name for it but it should be in the beginning of the section.

Do you know how to make the table if not heres to start you on equation #1

y = -x +4

you substitute for x and then add so for instance

x / y

1

therefore:

y = - (1) + 4

y = -1 + 4

y = 3

so the point is (1 , 3)

so now your fist row in your table would be looking like:

x / y

1 3

etc.....

do the rest until you have a line substitute for x to find y to have your points.

I hope this helps