Option D:
No, Claire should have gotten –2y = –8 instead of 2y = –8 in step 4.
Solution:
The system of equations are
4x – 2y = 4 – – – – (1)
3x + 3y = 21 – – – – (2)
Step 1: Multiply the equation (1) by 3 and equation (2) by 2
12x – 6y = 12
6x + 6y = 42
Step 2: Add the above equations.
⇒ 18x = 54
Step 3: Divide both sides of the equation by 18.
⇒ x = 3
Step 4: Substitute x = 3 in equation (1)
4(3) – 2y = 4
⇒ 12 – 2y = 4
Subtract 12 from both sides of the equation.
⇒ –2y = –8
Divide by –2 on both sides of the equation.
⇒ y = 4
Step 5: The solution is (3, 4).
But Claire's solution is (3, –4).
Claire's solution is not correct in step 4.
Option D is the correct answer.
No, Claire should have gotten –2y = –8 instead of 2y = –8 in step 4.
