Question

2x-6y=30
3x-9y=-27
Solve the system of equations by graphing ( i don't need the graphing done, I just need a walk through of how to solve this)

Answer 1

okay to do this first that the 1st eq'n
2x -6y = 30 and graph it.
I would graph this line by finding the x and y intercepts
x int (let y = 0): (15,0)
y int (lets x = 0): (0,-5)

next, take the second equation 3x-9y=-27 and graph it as well

x int (let y = 0): (-9,0)
y int (lets x = 0): (0,3)

wherever the lines meet is the sol'n

Answer 2

How did you come up with the 15 and -5??

Answer 3

for 15,

the x intercept occurs when y = 0. Sub y = 0 into the equation
-2x -6(0) = 30
-2x = 30
x = -25

the y intercept occurs when x = 0. Sub x = 0 into the equation
-2(0) -6y = 30
-6y = 30
y = -5

Answer 4

ooohhh I see...okay, so since there is more than one ordered pair, that means there is more than one solution?

Answer 5

The solution will be one point on the graph (x,y) where the two lines intercept. The lines should only cross once.

The (15,0) and (0,-5) are just two points so you can graph the first line.

Answer 6

OOOHHHHHHH DUH!!! lol

Answer 7

:)

Answer 8

my graph should look like an X ?

Answer 9

would the ordered pair be (0,3)

Answer 10

when these two equations are graphed, they are parallel; which means no solution.