Question

what is the solution of the following system -3x-2y=-12, 9x+6y=-9
a. (2,1)
b. no solutions
c.(-2,-1)
d. infinitely many solutions

Answer 1

substitute

Answer 2

wait r u the one i helped 3 minutes ago? lol

Answer 3

haha yea lol

Answer 4

cool same thing here, try it yourself first

Answer 5

9x+6y=-9= -1

Answer 6

remember the whole point of substituting is to make an equation with only 1 variable, which we can easily solve. we cannot solve a function with more than 1 variable

Answer 7

so first, choose a function, then isolate a variable, x or y, then put it in terms of the other variable, then substitute it into the other equation.

Answer 8

if u choose to isolate x, u shud have an equation like x = something, u then have to put it in terms of y, meaning the "something" has only y in it, nothing else

Answer 9

so say u choose -3x-2y=-12 to isolate x (or y if u want), u get x = 4 - 2/3 y, following the format i mentioned above "x = something, u then have to put it in terms of y, meaning the "something" has only y in it,"

Answer 10

then plug x = 4 - 2/3 y into the second equation, then solve for y because now x is eliminated (substituted by y).

Answer 11

11calcBC...do you think this problem would be more easily solved with elimination. Because if you use substitution, you will be dealing with fractions.

Answer 12

yes that would be easier actually, im just trying to make clear to her the concept of substitution lol

Answer 13

I understand..and you are doing a good job...thumbs up :)

Answer 14

lol thanks mate!

Answer 15

9x4+6x-2/3??

Answer 16

show me ur equation first

Answer 17

36+4???

Answer 18

u know how to use elimintation?

Answer 19

what is that lol?

Answer 20

thats when make u directly add or subtract functions to eliminate a variable

Answer 21

that would leave only 1 variable behind, which is what we always want

Answer 22

whats the answer

Answer 23

b. no solutions

Answer 24

u sure

Answer 25

If you use elimination\[-3x -2y = -12\]\[9x + 6y = -9\]Multiply top by 3 that gives you\[-9x - 6y = -36\]However if you add the top and bottom equations than the variables will cancel out. You will end up with: \[nothing = -45\]Therefore you have no solutions.

Answer 26

thanks

Answer 27

No problem.