Question

-2x + y = 1
-4x + y = -1

(3, 1)

(-1, 3)

(-1, -3)

(1, 3)

Determine which system below will produce infinitely many solutions.

-4x + 6y = 20
4x - 3y = -2

-2x + 4y = 18
4x - 8y = -36

3x - 2y = 5
-6x - 4y = -10

5x - 3y = 12
15x - 9y = 24

Answer 1

Solve for y for one equation and substitute the y with what you got into the other equation.

Answer 2

A system with infinitely many solutions is one that has all lines overlapping each other entirely. Find the system that has two equations that are actually just multiples of each other (This is how I would initially solve the problem, otherwise I'd resort to substitution as Grazes said).

Answer 3

For the first question is it b?

Answer 4

no its (1,3) srry i mistyped

Answer 5

Oh right I forgot this was actually two questions ^^" Yes the first question is (1,3)

Answer 6

Oh man i got it mixed up but thank you so much! can you help me with the second one too?

Answer 7

hahaha its ok i got that one! (:

Answer 8

My first post was my explanation to the second question.

Answer 9

is it D?

Answer 10

If D was contained two equations that are actually just multiples, then what number would you multiply the first by to get the second? Remember that the 12 and 24 are parts of this rule.

Answer 11

If D contained*

Answer 12

i think it"s B

Answer 13

Well it is, but I wanted Veronica to work for it =P

Answer 14

hahaha thank you guys so much! Can you help me with one more?
Choose the equivalent system of linear equations that will produce the same solution as the one given below.

4x - 2y = 6
2x + y = 5

-4x - 2y = 10
-4y = 4

-4x - 5y = -1
-7y = 5

3x + 2y = 6
7x = 12

4x + 2y = 10
8x = 16

Answer 15

i was thinking it might be c? im confused on this one.

Answer 16

is 4x - 2y = 6 the given solution ?
2x + y = 5

Answer 17

Same here, I don't see where the solution is

Answer 18

yes thats the given solution!

4x - 2y = 6
2x + y = 5

Answer 19

the x and y for the original solution is (2,1)
so find that one that gives u (2,1)

Answer 20

You're basically doing the same thing as before, except this time you just find the solution to your given system, and apply that to each of the answer choices. Whichever system is true with it is the answer.

Answer 21

alright im thinking it's A?

Answer 22

Plugging in the solution (2,1) does not make A true.

Answer 23

A is not true.. plug the points like snowfire said

Answer 24

how do i plug in the points? can you show the correct way in to setting it up? then i will solve it?

Answer 25

The 2 and 1 in (2,1) are the values for x and y respectively. Plug in 2 for every x and 1 for every y

Answer 26

plug 2 for x and 1 for y
4*2 - 2*1 = 6
2*2 + 1 = 5

Answer 27

C :)

Answer 28

i'm not very good at math :/ haha thank you for being so patient with me

Answer 29

it's okay, take ur time, and no it is not C

Answer 30

alright, it's b

Answer 31

dont just guess, try solving it

Answer 32

does -7*1 gives u 5? it does not so it is not b

Answer 33

OHHH!!! wait are you solving it by multiplying?

Answer 34

yeah sub the point to x and y and solve them.. i gave u an example at the top

Answer 35

the answer is D

Answer 36

its d :)

Answer 37

yup