Question

If the pair of linear equation $ax+2y=7$ and $2x+3y=8$ has unique solution then $a\ne$......... .

• A. $\frac{3}{4}$
• B. $\frac{-3}{4}$
• C. $\frac{4}{3}$
• D. $-\frac{4}{3}$

Answer 1

The correct option is C $\frac{4}{3}$

Condition for pair of linear equation having unique solution has :

$\frac{a_1}{a_2}\ne \frac{b_1}{b_2}$

$\Rightarrow \frac{a}{2}\ne \frac{2}{3}$

$\Rightarrow a\ne \frac{4}{3}$ .