Answer:
(x, y) = (4 7/9, 1 2/3)
Explanation:
You want to solve this system of equations using the elimination method.
Analysis
First of all, take a look at the coefficients of the variables:
x: 3 and 3. Subtracting one from the other will eliminate x
y: 4 and -2. Adding twice the second to the first will eliminate y.
Execution
The easiest elimination is accomplished by subtracting the second equation from the first:
(3x +4y) -(3x -2y) = (21) -(11)
6y = 10 . . . . . . . . . . simplify
y = 10/6 = 5/3 = 1 2/3 . . . . divide by the coefficient of y
Finding x
Substitute for y to find x.
3x +4(5/3) = 21
x +20/9 = 7 . . . . . . divide by 3
x = 7 -(2 2/9) = 4 7/9
The solution is (x, y) = (4 7/9, 1 2/3).
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Additional comment
A graphing calculator confirms this solution.