Two points are (0,-2) and (400,-102).
The first step for solving this problem is to multiply both sides of the bottom equation by -3.

Add the two equations together.
6x - 9y - 6x + 9y = 16 - 21
Eliminate the opposites.
-9y + 9y = 16 - 21
Remember that the sum of two opposites equals 0,, so the equation becomes the following:
0 = 16 - 21
Calculate the difference on the right side of the equation.
0 = -5
This means that the statement

is false for any value of x and y. That means that the answer to your question is (x,y) ∈ ∅,, or no solution.
Let me know if you have any further questions.
:)
Based on the numbers we have we can assume that she saves 3 times more each week than the last (1*3=3, 3*3=9).
Following this trend we would multiply the amount she saved the third week ($9) by 3 to get $27 for the fourth week.
Then, we would multiply the amount she saved the fourth week ($27) by 3 to get $81 for the fifth week.
Finally, to figure out how much she saved in the 5 weeks, we need to add each value up to get 1+3+9+27+81= $121 saved in 5 weeks
Answer: 10x + 4y + 2
The terms with an x are considered like terms so they could be subtracted.