Final answer:
To solve the system of equations using elimination, we manipulated the equations to cancel out x, solving for y, and then substituted the value of y back into one equation to solve for x. The final solution to the system is (3, 9).
Step-by-step explanation:
To solve the system of equations using elimination, we must manipulate the equations to eliminate one of the variables. We have the system:
First, let's multiply the second equation by 3 to make the coefficient of x the same (but opposite in sign) as in the first equation.
- 3(x + y) = 3(12)
- 3x + 3y = 36
Now we have:
Adding these equations together, we get:
- (-3x + 3x) + (2y + 3y) = 9 + 36
- 0x + 5y = 45
Now, we can solve for y:
Substitute y = 9 into the second original equation to find x:
- x + 9 = 12
- x = 12 - 9
- x = 3
The solution to the system of equations is (x, y) = (3, 9).