Question

Use substitution to solve the linear system. -x+3y=4 x+6y=14

Answer 1

When you are going to substitute a linear equation, You must factor out a variable like this: (I would be using the first equation since it is easier)

3y - 4 = x

x + 6y = 14

Now you know that x = 3y - 4 you can substitute it for the x value in the second equation like so.  

(3y - 4) + 6y = 14

Combine like terms

9y - 4 = 14

9y = 18

y = 2

Now you know what y is equal to 2 you can sub two in one equation to get the value of x: (I will be doing the second equation this time so I don't have to deal with the -x)

x + 6(2) = 14

x + 12 = 14

x = 2

Now we have our solutions

x = 2

y = 2

Answer 2

1 ) x= 3y-4

2) x= -6y+14