Question

3x-y=3 and
9x-y=4 by substitution method​

Answer 1

Let us number the equations :

$3x-y=3$ ........ (1)

$9x-y=4$ ......... (2)

Taking 1:

$\implies 3x-y=3$

${\underline{\boxed{\implies y=3x-3}}}$ ..(3)

Taking 2:

$\implies 9x-y=4$

$\implies 9x -(3x-3) =4$

$\implies 9x-3x+3=4$

$\implies 6x=4-3$

${\underline{\boxed{\red{.\degree.x=\frac{1}{6}}}}}$

Now from.... 1

$\implies 3x-y=3$

$\implies 3\times\frac{1}{6}-y=3$

$\implies \cancel{3}\times\frac{1}{\cancel{6}^{2}}-y=3$

$\implies \frac{1}{2}-y=3$

$\implies y = \frac{1}{2}-3$

$\implies y =\frac{1-6}{2}$

${\underline{\boxed{\purple{.\degree. y=\frac{-5}{2}}}}}$

$<marquee scrollamount="1300">♥Answer by Rishabh♥</marquee>$