Question

Solve the system by graphing. Help Please?

y=3x+6
y=-3x

Answer 1

it is easier to solve by writing
\[-3x=3x+6\] and solving for \(x\)

Answer 2

you get \(-6x=6\) and so \(x=-1\)
then if \(x=-1\) you have \(y=-3\times -1=3\)

Answer 3

I disagree, Satellite, it's easier to solve by graphing it in basic y = mx + b method

Answer 4

i already have the first one, i just don't know how to do the second one.
And I'd wrather just stick with y=mx+b Sorry(:

Answer 5

@Compassionate do you know how to solve the second one? I don't know what to do because there is only m

Answer 6

There is no y-intercept for the second on. So your solution will lie cross the y-axis only. That is, go up 3, and over 1, then graph.

Answer 7

not sure what you mean by :"second one"
the answer is not a line, it is a point, namely \((-1,3)\)

Answer 8

Only given the slope = only graph the slope. It should be a straight line.

Answer 9

Right, but there is no y-intercept, Satellite. So you're just graphing (-3, 1)

Answer 10

\[- \frac{ 3 }{ x } = - \frac{ 3 }{ 1 } = \frac{ -3 }{ 1 }\]

Answer 11

so, i did what you said but i got parallel lines. @satellite73

Answer 12

y=mx+c is straight line graph equation. 3 is gradient so it steep by 3. 6 is y intercept

Answer 13

yes, but then the second equation is also a straight line, and there is no solution because you get parallel lines right?

Answer 14

yes, exactly what i got. but for the second equation it should be a parallel line to the one you just drew, therefore no solution.

Answer 15

right? @jimswig88

Answer 16

y=-3x is same gradient sloping opposite to that line cutting through origin 0,0

Answer 17

i have (1,-3) for the second line.

Answer 18

@jimswig88

Answer 19

okay. Thanks!!

Answer 20

yes both lines intercept at -1,3