Question

solve the system of equations by elimination 3x+6y=5
-3x-3y=7

Answer 1

notice you have +3x in equation 1 and -3x in equation 2

Answer 2

they add to

3x + (-3x) = 3x - 3x = 0x = 0

so effectively adding them gives you 0 (which goes away)

Answer 3

this means that if you added both equations, you would get

3x+6y=5
-3x-3y=7
-----------
0x + 3y = 12


so we know that 3y = 12, which means y = ???

once you figure out y, you can solve for x

Answer 4

thank you :)

Answer 5

you're welcome

Answer 6

waiiiit I needed help solving x

Answer 7

y=4

Answer 8

but somehow I got 3x=-19 for x and it doesn't go

Answer 9

good y = 4 is correct

Answer 10

3x+6y=5

3x+6*4=5 ... plug in y = 4

3x + 24 = 5

3x = 5 - 24

3x = -19

x = -19/3

you can leave it as a fraction or convert to decimal form (it will be approximate though)

Answer 11

OR you can pick on the second equation

-3x-3y=7

-3x-3*4=7

-3x - 12 = 7

-3x = 7 + 12

-3x = 19

x = 19/(-3)

x = -19/3

either way, you'll get x = -19/3

Answer 12

okay I thought I did something wrong

Answer 13

nope you did it perfectly

Answer 14

it's perfectly possible to get a fraction as an answer

Answer 15

ahh okay then thanks again

Answer 16

sure thing