To eliminate a cariable in a system of equations, we multiply the variable by a factor that will make both coefficients of the variable to be equal.
Thus, we multiply the coefficient of y in the second equation by a factor that will make it equal to the coefficient of y in the first equation. i.e. multiply 1/2 by a factor that makes it equal to 3/4. and the factor is 3/2.
Therefore, the third option is the correct answer.
