Question

Determine which method works, substitution or elimination? 4x^2+3y^2=42x^2-6y^2=-3

Answer 1

Given:

$\begin{gathered} 4x^2+3y^2=4 \\ \\ 2x^2-6y^2=-3 \end{gathered}$

Find the method .

Sol:

$\begin{gathered} 4x^2+3y^2=4..............(1) \\ \\ 2x^2-6y^2=-3.............(2) \end{gathered}$

2eq(1) + eq(2) then,

$8x^2+6y^2=8$

Then apply the elimination method.

$\begin{gathered} 8x^2+6y^2=8 \\ 2x^2-6y^2=-3 \\ --------- \\ 10x^2=5 \\ \\ x^2=\frac{5}{10} \\ \\ x=\sqrt{\frac{1}{2}} \end{gathered}$