Question

What is the value of the y-coordinate of the solution to the system of equations?

x+3y = 2
-3x-8y=4

Plese show steps on how to solve thanks!

Answer 1

(X+3Y=2)*3
3X+6Y=6
-3X-8Y=4 add these equations your gona get
-2Y=10
Y=-5

Answer 2

How did you get that? what steps did you use? I've never done these before xD

Answer 3

like why would you times everything by 3, i dont know.

Answer 4

holda man

Answer 5

just mulitply whole equation by 3 i mean the first one and then add both the equations

Answer 6

to elimintate x

Answer 7

but why 3?

Answer 8

from my perspective, i dont know why we are doing that with 3? is it because 3 is the y cordinate? i dont know. so i am lost

Answer 9

because in the second equation its -3x so we are equating by multiplying 3 in the first one and obtaining equal and opposite and hence eliminating x from both the parts

Answer 10

still any doubts

Answer 11

yep, when looking at the problem i am asking myself, what is the first thing i should do and why.

Answer 12

see firstly u have to eliminate x in order to get the value of y
right?

Answer 13

for x elimination we are multiplying the first equation by 3

Answer 14

3x+9y=6
-3x-8y=4

add the above two equations
y=2

Answer 15

sorry after addition y=10

Answer 16

See nits, i understand yours because his said 3x+6y=6y

Answer 17

so basically your just multiplying out the x, by 3 i knew there was something wrong with his example.

Answer 18

yes

Answer 19

thats why i was so confused, lol because 3 x 3 = 9 , where did he get 6 from . LOL

Answer 20

yes.........any other doubts

Answer 21

not doubts but question as to why we use that number 3, like if there was another problem. where did the 3 come from that we used?

Answer 22

was the 3 from the lower problem with 3x?

Answer 23

suppose....
5x+4y=10
x+6y=9

then for eliminaton of y we would have multiplied 2nd equation by 5

5x+4y=10
5x+30y=45
and then subtract the above two equations
which would give
-26y=-35
y=35/26

Answer 24

THank you , That is very clear and i understand it now =D

Answer 25

Left handed brain, its stubborn to take in information that doesn't add up.