Question

Y=x+4 y=3x solve by substitution

Answer 1

Y=x+4 becomes 3x=x+4 by substitution then you subtract x to get 4 by itself then you will have 2x =4. So your answer is x=2.

Answer 2

So what i did was i wrote down the problem Y=x+4 

i plug in 3x where the y is so you would have the problem rewritten as 3x=x+4.

Now the first thing I did was to take x and change it to -x:  3x=x+4
                                                                                             -x -x
Then i cross out the two x's and then take 3x and subtract it to x cause there's an understood 1 next to it which gave me 2x.: 2x=4

After that i put the 2 under 2x and 4 because this is where I divide. Cross out the two 2's. then take 4 divide it by 2 which he answer is x=2. Hope this helped! :D