Answer:
Solution = (2, 11)
Step-by-step explanation:
Step-by-step explanation:
In this question, they want you to solve a system of equations by addition. Because we already have two variables with opposite signs, we can add them together and solve for x.
Step 1: Add the two equations together
1. 4x + 5x - y + y = -3 + 21
Step 2: Simplify
2. 4x + 5x - y + y = -3 + 21 → 4x + 5x = 18 → 9x = 18
Step 3: Solve for x
3. 9x = 18 → x = 2
Step 4: Substitute 2 for x in either one of the original equations
4. 4(2) - y = -3
Step 5: Solve for y
5. 8 - y = -3 → -y = -11 → y = 11
Solution = (2, 11)
Hope this helps you out :)