Question

solve the system by graphing
{-2x=2y-4
{2x-y=-5
Help walk through this please.

Answer 1

-2x=2y-4
multiplying both sides of this equation by -1 gives
2x=-2y+4
so replace 2x in the second equation with (-2y+4)

Answer 2

oops solve by grahping

Answer 3

forgot to read that part

Answer 4

write both equations in the form y=mx+b
this form is fun to play with because it tells you the slope m and the y-intercept b

Answer 5

-2x=2y-4
2x=-y-5

Answer 6

@freckles ?

Answer 7

yes you need to write those in y=mx+b form

Answer 8

for example
-2x=2y-4
can be written in that form by doing the following:
add 4 to both sides
-2x+4=2y
2y=-2x+4 (just wrote the equation the other way around)
divide 2 on both sides
y=-x+2
so here you see we have a slope of -1 and a y-intercept of 2

Answer 9

try doing this with the other line you have there

Answer 10

2x=-y-5
so do i add the 5 to 2x?

Answer 11

here is a nice picture
http://www.wolframalpha.com/input/?i=-2x%3D2y-4+%2C2x-y%3D-5

Answer 12

oh okay