Question

can someone help me solve this problem by using substitution
2x+y=-4
y=x-1

Answer 1

the second equation tells you another way to write "y" (because y EQUALS (x-1) )

SO

In the FIRST equation, wherever there is y you can substitute (x-1)

do that and then write the new equation here

Answer 2

2x+x-1=-4

Answer 3

OK good

that is the mains step - the substitution

now add 1 to each side
(and simplify the x terms if oyu can)

Answer 4

would x = -1
or did i do it wrong?

Answer 5

yes that is correct

when you do what I said abpove you get 3x = -3

so if x = -1

use the SECOND equation to find y

Answer 6

okay

Answer 7

y=-2?

Answer 8

yes - good

the best thinig when you have a solution to equations like this is to put th enumbers into both equations and check that they are true

so x=-1 y=-2

in th esecong equation is
-2 = -1 -1

this is true.

Now check th efirst one in th esame way..

Answer 9

okay

Answer 10

both equations are right, thank you :)