What substitution should be used to rewrite 6(x+5)^2+5(x+5)-4=0 as a quadratic equation? u=(x+5) u=(x-5) u=(x+5)^2 u=(x-5)^2

To rewrite the given equation $6(x+5)^{2}+5(x+5)-4=0$ as a quadratic equation, we can use the substitution $u=(x+5)$. <br /><br />By substituting $u=(x+5)$, the equation becomes $6u^2+5u-4=0$, which is a quadratic equation in terms of $u$.