Question

Solve the following system of equations. Please show your work to receive full credit.
x - y = 10
2x + y = 2

Part 2:
Explain which method you chose to solve the system and why you felt it was the best choice.

Please Use Substitution

Answer 1

x - y = 10
2x + y = 2
rearranging the first equation by taking -y to the other side:
x = 10 + y
since we have found what x is we can substitute it in the other equation like so:
2(10 + y) + y = 2
20+2y+y = 2
20+3y = 2
3y = 2-20
3y = -18
y = -18/3
y = -6
and since we know x = 10 + y
x = 10 - 6
x = 4

Answer 2

And the second part,
I would've used elimination however since you wanted me to use substitution, I would say that I choose substitution because by looking at the first equation I can easily rearrange the equation and plug it as there aren't very big numbers, Moreover it would consume less time than canceling out the equations.