Question

How many solutions are there to the following system of equations?



3x - 9y=0
-x + 3=-3



A.
0


B.
2


C.
1


D.
infinitely many

Will medal/fan

Answer 1

@confluxepic

Answer 2

@Loser66

Answer 3

@TheSmartOne

Answer 4

Lets solve the 2 equations.

Answer 5

So which method do you like to solve them by?
Substituion, elimination, or graphing?

Answer 6

Substituion.

Answer 7

So lets solve for x in this equation

\(\sf -x + 3=-3\)

Answer 8

We can add x to both sides and then add 3 on both sides. And we will have isolated x.

Answer 9

like this?\[3=-3+x?\]

Answer 10

yup and then just add 3 on both sides again :)

Answer 11

\[3+3=-3+x+3?\]

Answer 12

and \(\sf -3+3 =0\)

And what is \(\sf 3+3=?\)

Answer 13

6

Answer 14

So now we have these 2 equations

\(\sf 3x - 9y=0 \\x=6\)

Answer 15

So lets plug in x=6 into 3x - 9y=0

\(\sf 3x - 9y=0\)
\(\sf 3\times (6) - 9y=0\)

Solve for y :)

Answer 16

Oh and just a tip, 2 equations can NEVER have 2 solutions. So if you ever see 2 as a answer choice for this type of question, you can eliminate it.

Answer 17

okay
\[3x6=38-9y=29y???\]

Answer 18

ok... what is \(\sf 3 \times 6=?\)

Answer 19

38

Answer 20

Actually no.

\(\ 3 \times 6 = 6+6+6=?\)

Answer 21

18.... Then I must've failed on my other quizes <.<'

Answer 22

correct.

and \(\sf 18-9y=0\)

Add 9y to both side and then divide by 9. And you get the vaule of y.

But we can stop right here. We have gotten that the answer is (x,y) which is (6,y) (which is what we will get when we solve for y)

And (6,2) is only one point. So we only have 1 solution.

Answer 23

okay.

Answer 24

Well I hope that helps :)