Question

The elimination method is ideal for solving this system of equations. By which number must you multiply the second equation to eliminate the y-variable, and what is the solution for this system?
x + 3y = 42
2x − y = 14

A: Multiply the second equation by -3. The solution is x = 12, y = 9.
B: Multiply the second equation by -2. The solution is x = 12, y = 10.
C: Multiply the second equation by 2. The solution is x = 15, y = 9.
D: Multiply the second equation by 3. The solution is x = 12, y = 10.

Answer 1

     x+3y=42
+3(2x−y=14)
__________
7x=84

x=12 and since x+3y=42

12+3y=42

3y=30

y=10

So the solution is (12, 10)

Thus the answer is D.