Question

x+y=7 , x+y=3 infinite solution

Answer 1

Good guess, but no. Can you think if ANY two values that add to make 7 AND 3?

Answer 2

how can i tell if this is one solution infinite numbers of solutions or no solution at all

Answer 3

infinite solution mean that the equations are for the SAME line

like
x=y and x-2 = y-2

No solution means the lines are parallel and never meet

they are parallel if they have the same SLOPE

y=2x+4 and 2y = 4x+8 for example

Answer 4

ANY other pair of straight lines will meet at ONE point - so ONE solution

Answer 5

CORRECTION above:

they are parallel if they have the same SLOPE

y=2x+4 and 2y = 4x-6 for example


( the previous example was the SAME line)

Answer 6

Solve the system. There are only a few possible outcomes.

1) x = 2, y = 4 -- This is a solution and it is the only solution.
2) 3 = 7 -- Well, that's just silly. No solution at all.
3) 4 = 4 -- This is super obvious. x and y don't matter. Infinitely many solutions.

Answer 7

I kind of don't understand like what if its like x+y=4

Answer 8

nt sure I follow you @tkhunny
(2,4) is not a solution

we have y= -x+7
and y= -x+3

these are 2 parallel lines therefore NO solution

Answer 9

no its not the at all
its x+y=7
x+y=3

Answer 10

they are the SAME

x+y=7

subtract x from each side gives
y = -x+7

(you can do the same with your other equation too :-)

Answer 11

so it it one solution

Answer 12

It's called an example.

1) Something consistent, LIKE x = 2 and y = 4. 1 solution.
2) Something silly, LIKE 3 = 7. No solution.
3) Something obvious, LIKE 5 = 5. Lot's of solutions.

Now, you solve your system and see which type you get.

Answer 13

You need to read the example I gave above

If the slope is the same there is no solution
if the lines are identical there is infinite solutions
otherwise there is one solution

Do your lines have the SAME slope?

Answer 14

look I am not sure aright and I feel like this is unhelpful because it seems that your becoming frustrated

Answer 15

OK - but you are evidently studying the equations of straight lines

so - I have to assume that you know about slope and equations etc.

Therefore I explained that you can tell if there is no solution by looking at the slope

the easiest way to see the slope is to arrange the equations like I did

we have y= -x+7
and y= -x+3


these are the SAME equations that you have - do oyu understand how I got there?

Answer 16

ok now I'm following

Answer 17

now what

Answer 18

so if they have the same slope they look like this and never meet



the solution is where the lines meet - so there is no solution

Answer 19

if they are the SAME line then they look like this:



the two lower lines are the same - so there are infinite soluitons

ANY other pair looks like this:


they meet at one point - so one solution