Question

solving systems using substitution

x=y
x+2y=3

Answer 1

hey julian

Answer 2

hey sandra

Answer 3

so to solve by substitution, you replace one of the variables in a second equation with the value for that same variable in the first equation. This replacement is called substitution.

Answer 4

so in your example, we want to replace the x in the second equation, with the value of "x" in the first - i.e. subsitute for x in the second equation

Answer 5

ok

Answer 6

so instead of x + 2y =3, we use "x=1" in the first equation to replace the "x" with "y"
1. x + 2y = 3, and given x=y
2. (y) + 2y = 3
3. 3y = 3
4. y = 1

Answer 7

in general, all substitution problems come down to "isolating" a variable in one of the given equations (getting it by itself - in this problem it's already started that way with x=y), and then using that value in place of the same variable in another equation. replacement = subsitution

Answer 8

oh ok im staring to get it now

Answer 9

Thank you!!!!! you really helped

Answer 10

ok np, post more problems if you want to work through another one!

Answer 11

ok