The first one becasue it extends more than the second one
Let the balance = Y and the number of weeks = x
She takes out 15 per week, so multiply 15 by x ( the number of weeks) to get 15x.
You would then want to subtract that from the amount she started with in her account.
The equation becomes: Y = 150 - 15x
B is the answer!!!!!!!!!!!!!!!!!!!!!!!!!
The easiest way to solve this is by elimination.
3x - y = 6
6x + y = 21
Since you have a negative and positive y with the same coefficients (1), they cancel, and you add the other terms so it would look like:
9x = 27
Then solving for x leaves you with x = 3
Then you take the x value of three and plug it into to either of the equations, so
3(3) - y = 6
9 - y = 6
subtracting 9
-y = -3
then dividing by -1
y = 3
so the solution is x = 3 y = 3 or (3,3)
