To solve this system using substitution, start by writing them next to each other. You can see that the y value is already isolated with its own value (x - 7).
So, since y equals that expression, you can substitute it into your first given equation for the y. This leaves you with: 5x + 2(x - 7) = 14
Then, use the distributive property to simplify your equation. This ends up with: 5x + 2x - 14 = 14
Combine like terms by adding the coefficients in front of your x’s. This results in: 7x - 14 = 14
Begin to isolate your variable by adding 14 to both sides. This leaves you with: 7x = 28
Divide both sides by 7 to find the value of x in your solution. This results in: X = 4 So you know that the x value in your final ordered pair will be a 4. At his point you could eliminate answer options and find the correct one, however to find your y value:
Substitute in your x to the simplest equation you were given in the system at the beginning. This would be y = x - 7 Plugging in the value leaves you with: y = 4 - 7 Subtract to find your final answer. 4-7= -3
So your y value is -3.
This makes your final ordered pair option C. (4, -3)
