Question

For what value of m, the system of equations mx + 3y = m – 3 , 12x + my = m will have no solution?

• A. -4
• B. 4
• C. -6
• D. 6

Answer 1

The correct option is C

-6

$\frac{m}{12}$ = $\frac{3}{m}$ $\ne$ $\frac{-(m-3)}{-m}$

$\Rightarrow$ $m^2=36$

$\Rightarrow$ m = $\pm$6 --------(1)

$\Rightarrow$ 3m $\ne$ m(m-3)

$\Rightarrow$ $3m\ne m^2-3m$

$\Rightarrow$ $m(m-6)\ne 0$

$\Rightarrow$ m $\ne$ 0 and 6 -------(2)

So, from (1) and (2) m = -6