Question

I'd be very grateful for help!

Solve the following system of equations. Please show your work to receive full credit.
x - y = 19
2x + y = 2

Answer 1

if you add the equations, you get this

x - y = 19
2x + y = 2
----------
3x + 0y = 21


3x = 21

x = ??

Answer 2

oh wow 7?

Answer 3

so if x = 7, then what is y

Answer 4

so I plug in 7 for one of the equations?

Answer 5

correct, pick any equation, replace x with 7, then solve for y

Answer 6

unsure if this is right, but 12? if it isnt I know why.

Answer 7

let's pick the first equation

Answer 8

x - y = 19

7 - y = 19 ... plug in x = 7

-y = 19 - 7

-y = 12

-1y = 12

y = 12/(-1)

y = -12

Answer 9

so you were off by a sign

Answer 10

Oh! I rushed it a tad, that's a simple fix! I appreciate the help you are a god haha :D

Answer 11

and is this substitution method?

Answer 12

no it's the elimination method

Answer 13

go back up the very top and you'll see that we're adding the equations and one variable is eliminated that way

Answer 14

oh wow I should of understood that...

Answer 15

the substitution method would have us isolate a variable, then substitute or plug it into the other equation

Answer 16

that's ok

Answer 17

just keep practicing and you'll get a better hang of things

Answer 18

Im doing a few practice problems, Using the method you have shown me:)

Answer 19

I'm glad it's clicking