Question

Select the correct answer.

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
OA. Multiply the second equation by-3. The solution is x= 12, y=9.
OB. Multiply the second equation by -2. The solution is x = 12, y=10.
OC. Multiply the second equation by 2. The solution is x = 15, y = 9.
OD. Multiply the second equation by 3. The solution is x = 12, y = 10.

Answer 1

Multiply the second equation by 3. The solution is x = 12, y = 10.

Explanation:

The given equations are :

x+3y= 42 ....(1)

2x - y = 14 ...(2)

For elimination method,

Multiply the second equation by 3.

6x-3y=42 .....(3)

Adding equations (1) and (3).

x+3y+6x-3y=42+42

7x = 84

x = 12

Put the value of x in equation (1).

12+3y= 42

3y = 30

y = 10

So, x = 12 and y = 10. Hence, the correct option is (d).