Question

Solve the system of linear equations by substitution

Answer 1

There is the equal values method, so you can do:

x-4 = 4x-10 (remove x from both sides)
-4 = 3x -10 (add ten to both sides)
6 = 3x  (devide by 3x)
2 = x

Check: (by plugging it into the equation)
y = 2-4 and y = 8-10
y = -2 and y = -2
that's matches so it is correct...
 YOUR ANSWER IS:
(2, -2)

I hoped I helped sort things out, and have a great day!

Answer 2

Y = x-4
y = 4x-10

Compare both the equations, 
4x-10 = x-4
4x-x = 10-4
3x = 6
x = 6/3
x = 2

Now, substitute it in 1st equation, 
y = 2-4 = -2

In short, Your Answer would be (2, -2)

Hope this helps!