I need to use substitution method to find all solutions of the systems of equations for x^2 + y^2=25 and y=2x. I need help. The equations are in brackets.

Question

anonymous · Answer

Substitute y=2x into the first equation. Then simplify it and you have a quadratic in x which you can solve by factorisation (possibly), completing the square or the formula.

anonymous · Answer

How do you work it out bfsgd? Help me please.

anonymous · Answer

Anyone!!! Help me.

anonymous · Answer

$$x^2 + 4x^2 = 25 \text{ so } x^2 = 5$$

anonymous · Answer

Ok. And then bfsgd.

anonymous · Answer

Then we take square roots. There are two solutions for x namely $$x = \pm \sqrt{5} $$ and y=2x so $$y=\pm 2\sqrt{5}$$