Question

(Solving quadratics by square roots)

3k^2 = 243

I have finals tomorrow and it says solve each equation by taking square roots but I’m confused on it. Plz help!!!!

Answer 1

${3k}^{2} = 243 \\ = > {3k}^{2} - 243 = 0 \\ = > 3( {k}^{2} - 81) = 0 \\ = > 3[(k) ^{2} - {(9)}^{2} ] = 0 \\ = > 3(k - 9)(k + 9) = 0 \\ = > (k - 9)(k + 9) = 0 \\ = > k = 9 \: \: or \: \: - 9$

Hope you could get an idea from here.

Doubt clarification - use comment section.