Question

elimination method x+y=4 6x-3y=9​

Answer 1

Answer:

$\sf x+y=4\dots(1)$

$\sf 6x-3y=9$

• simplify

$\qquad\quad\displaystyle\sf {:}\longrightarrow 2x-y=3 \dots (2)$

• by adding eq (1) and eq (2)

$\qquad\quad\displaystyle\sf {:}\longrightarrow 3x=7$

$\qquad\quad\displaystyle\sf {:}\longrightarrow x=\dfrac {7}{3}$

• substitute the value in eq (1)

$\qquad\quad\displaystyle\sf {:}\longrightarrow \dfrac {7}{3}-y=4$

$\qquad\quad\displaystyle\sf {:}\longrightarrow \dfrac {7}{3}-4=y$

$\qquad\quad\displaystyle\sf {:}\longrightarrow y=\dfrac {7-12}{3}$

$\qquad\quad\displaystyle\sf {:}\longrightarrow y=\dfrac {5}{3}$

$\therefore \sf(x,y)= (\dfrac {7}{3},\dfrac {5}{3})$