Question

How to solve x+4y=27 by using substitution method?
x+2y=21

Answer 1

X=21-2y

X+4Y = 27

21-2y + 4y = 27

y= {27-21}÷2

y=3

Answer 2

x+4y=27.......i

x+2y=21.......ii

y=3

putting the value

x+2×3=21

x=15

so x,y=15,9