Question

can someone please help me with this? its making my head explode because I am not sure if you need to use the method of substitution.
what is the point of intersection?
y=-2x
2x+3y=-12

Answer 1

Use it anyway!

Answer 2

If you don't know how to do it, then use the method you know!

Answer 3

Math Rule #159: Do what you know works.

Answer 4

yeah but will that give me my intersection?

Answer 5

The point of intersection is basically the values of x and y.

Answer 6

So if \(x=a\) and \(y=b\) this means the point of intersection is \((a,b)\).

Answer 7

solving 2 equations like this with algebra is the same thing as finding where two lines intersect.

Answer 8

oh okay because my answer was 0,-6 and I think that's wrong

Answer 9

when x is 0, the first equation gives you y=0
which is not -6

your solution has to work for both equations

Answer 10

try again

y=-2x
2x+3y=-12

replace y with -2x in the 2nd equation

2x + 3(-2x) = -12

can you simplify this ?

Answer 11

x=-4

Answer 12

-3

Answer 13

x=3

Answer 14

are you guessing ?
the first thing is simplify 3*-2*x to -6x in
2x + 3(-2x) = -12

to get
2x -6x = -12

now you have 2 x's takeway 6 x's. how many x's do you have ?

Answer 15

-4x

Answer 16

so you have
-4x= -12

divide both sides by -4

-4x/-4 = -12/-4

on the left, -4/-4 is 1, and 1x is x
x = ?

Answer 17

-3

Answer 18

3

Answer 19

minus divided by minus makes a plus

-12/-4 is +3

x= 3

now find y using y=-2x
(replace the x with 3 to find y )

Answer 20

your really good thank you very much

Answer 21

yw