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.