Answer:
Solution ( \(\frac{26}{7}\) , \(\frac{-3}{7}\))
Step-by-step explanation:
Given : 3x - 2y = 12 and 6x + 3y = 21.
To find : Solve the system of equations and choose the correct ordered pair.
Solution : We have given
3x - 2y = 12 -------(1)
6x + 3y = 21-------(2)
Multiplying the equation(1) by 2 , it become.
6x - 4y = 24 .
Now subtract it from equation (2).
6x + 3y = 21
(-)6x - (+)4y = (-)24 .
____________
0 + 7y = -3.
On dividing both sides by 7.
y = \(\frac{-3}{7}\).
Plug the y = \(\frac{-3}{7}\) in equation 2 .
6x + \(3*\frac{-3}{7}\) = 21
6x + \(\frac{-9}{7}\) = 21.
On multiplying both sides by 7
42x -9 = 21 *7 .
42x -9 = 147 .
On adding both sides by 9
42x = 147 + 9 .
42x = 156.
On dividing both sides by 42.
x = \(\frac{156}{42}\).
x = \(\frac{26}{7}\).
Therefore, Solution ( \(\frac{26}{7}\) , \(\frac{-3}{7}\))