Answer:
3x+y=7
X=2y
collecting like terms:
3x+y=7
x-2y=0
eliminate like terms:
(first multiple both equations with 0 and 3)
(3x+y=7)0
(x-2y=0)3
The result is as follows:
3x+y=7
3x-6y=0
5y=7
devide by 5
y=1.4
then we solve for X now cause we know the value of y
3x+1.4=7
let's collect like term
3x=7-1.4
3x=5.6
devide by 3 both sides
X= 1.87
3(1.87)+1.4=7