The pair of equations 2 x+3 y=5 and 4 x+6 y=15 has
(a) a unique solution
(b) exactly two solutions
(c) infinitely many solutions
(d) no solution
The pair of equations 2 x+3 y=5 and 4 x+6 y=15 has
(a) a unique solution
(b) exactly two solutions
(c) infinitely many solutions
(d) no solution

Answer: (d) no solution
Here, a_{1}=3, b_{1}=2 k, c_{1}=-2, a_{2}=2, b_{2}=5 and c_{2}=1
\therefore \frac{a_{1}}{a_{4}}=\frac{3}{2}, \frac{b_{1}}{b_{L}}=\frac{2 k}{5} and \frac{c_{1}}{c_{L}}=\frac{-2}{1}
For parallel lines, we have:
\frac{a_{1}}{a_{3}}=\frac{b_{1}}{b_{7}} \neq \frac{c_{1}}{c}
Sol:
The given system of equations can be written as:
2 x+3 y-5=0 and 4 x+6 y-15=0
The given equations are of the following form:
a_{1} x+b_{1} y+c_{1}=0 and a_{2} x+b_{2} y+c_{2}=0
Here, a_{1}=2, \mathrm{~b}_{1}=3, \mathrm{c}_{1}=-5, \mathrm{a}_{2}=4, \mathrm{~b}_{2}=6 and \mathrm{c}_{2}=-15
\therefore \frac{a_{1}}{a_{2}}=\frac{2}{4}=\frac{1}{2}, \frac{b_{1}}{b_{2}}=\frac{3}{6}=\frac{1}{2} and \frac{c_{1}}{c_{2}}=\frac{-5}{-15}=\frac{1}{3}
\therefore \frac{a_{1}}{a_{2}}=\frac{b_{1}}{b_{2}} \neq \frac{c_{1}}{c_{z}}
As a result, the given system has no solution.