Question

Which of the below systems of equations matches the following graph?


SEE GRAPH BELOW
x – y = 1
3x – 2y = 8

x – y = –1
3x + 2y = –8

x + y = 1
3x – 2y = 8

x + y = –1
3x + 2y = –8

Answer 1

you need a line with intercepts x = -1, y = 1

and a line with a y intercept of -4 and an x intercept of - 2 2/3

Answer 2

@campbell_st
im still confused as to what to do?

Answer 3

to start with, I looked at the graphs and worked out where each line cuts the x and y axes.

in each pair... look at the 1st line and substitute y = 0 and find a value for x

x - y = 1 so x = 1

x - y = -1 x = -1 y = 1

x + y = 1 x = 1

x + y = -1 x = -1 y = -1

so the options are the 2nd and 4th lines now substitute x = 0 into these 2 lines... and you are looking for y = 1

so the 2nd answer seems to be the one...

check by finding the intercepts of the 2nd line... looking at the graph ou know is y= -4 and x = -2 2/3


so look at 3x + 2y = -8 let x = 0 so 2y = -8 or y = -4

y = 0 3x = -8 x = -8/3 or - 2 2/3

so its the 2nd answer...

hope this helps

Answer 4

Thank you so much! I get it now (: