Question

Solve the system of equations and choose the correct ordered pair. 3x-2y=12 and 6x+3y=21

Answer 1

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 ( $\frac{26}{7}$ ,  $\frac{-3}{7}$)