Which of the following would not be the result of a substitution in the following system? 2x + y = 7y - x= 1a. 7 - 2x- x = 1b. 2x + x + 1 = 7c. 2(y + 1) + y = 7

The correct option is:

C.

To find which of the given options are not the result of a substitution in the given system, we need to isolate the variable in function of the other variable, and then substitute it.

So, substituting and discarding, we have:

- First equation:

Isolating "y", we have:

Then, substituting it into the second equation, we have:

We have that it's a result of a substitutiong in the following system (option A)

- Second equation:

Isolating "y", we have:

Then, substituting it into the first equation, we have:

Have a nice day!

687.09 dollars       happy now

step-by-step explanation: 6870

1857 times .63 equals 1169.91 subtract that from 1857 you get 687.09