Solve the system of equations using substitution.
4x + y = 12
y = 2x

(2,4)

Step-by-step explanation:

One way to solve a system is called substitution.  Because one of the equations is set up in a way where we know what Y equals in terms of X we can plug that into the other equation for Y and then we can solve for X because we will then only have one variable.  Since the second equation tells us that y is equal to 2x we will plug 2x into the first equation where we see Y and that gives us

4x+2x =12

now we can combine and solve for x

6x=12

x=2

and now that we have 2 we can plug that back into the second equation and solve for y

2 times 2 = y

y=4 so the answer is (2,4)

I hope this helps and please don't hesitate to ask if there is anything still unclear!

e.

step-by-step explanation:

because there are always 10 numbers in a phone number.