Question

For the following system, use the second equation to make a substitution for y in the first equation. 3x + y = 1 y + 4 = 5x What is the resulting equation? 1. 3x + 5x - 4 = 1 2. 3x + 4 - 5x = 1 3. 3x + 5x + 4 = 1

Answer 1

The answer is A.

Explanation:

So we have the two equations:

`3x+y=1\\y+4=5x`

To make a substitution of the second equation into the first equation, we need to isolate the y variable in the second equation. Thus:

`y+4=5x\\y=5x-4`

Now, we can substitute this into the first equation. Therefore:

`3x+y=1\\3x+(5x-4)=1\\3x+5x-4=1`