Question

Claire completed the steps to solve the system of equations. 4 x minus 2 y = 4. 3 x + 3 y = 21. Step 1 12 x minus 6 y = 12. 6 x + 6 y = 42. Step 2 18 x = 54. Step 3 x = 3. Step 4 4 (3) minus 2 y = 4. 12 minus 2 y = 4. 2 y = negative 8. Y = negative 4. Step 5 Solution is (3, negative 4). Is Claire's solution to the system of equations correct? Explain why or why not.

Answer 1

The other dude is right.

Explanation:

Answer 2

Claire should have gotten –2y = –8 instead of 2y = –8 in step 4.

Explanation:

Following the steps taken :

4x - 2y = 4 - - - (1)

3x + 3y = 21 - - - (2)

Multiply (1) by 3 and (2) by 2

12x - 6y = 12 - - - (3)

6x + 6y = 42 - - - (4)

Add (3) and (4)

18x = 54

x = 54/18

x = 3

Put x = 3 in (1)

4(3) - 2y = 4

12 - 2y = 4

-2y = 4 - 12

-2y = - 8 (this is where the mistake lies)

It shouldn't be 2y = - 8 as stated