Question

x=y; x+2y=3

Answer 1

x=1
y=1

Answer 2

how did you find that?

Answer 3

substitution
(y)+2y=3
sincey and 2y are like terms
add 2y to y
3y
3y=3
divide
3y/3 = 3/3
simplify the ledt canceling the common factors
y=3/3
simplify
x=1
y=1