Question

Resolver a equação: |1 2x 4| |x 2 2| |1 5 1| = 24​

Answer 1

Resposta: x=2 ou x=10

Explicação passo-a-passo:

$\left|\begin{array}{ccc}1&2x&4\\x&2&2\\1&5&1\end{array}\right|=24\to\\\\1.2.1+x.5.4+1.2.2x-(4.2.1+2x.x.1+1.5.2)=24\to\\\\2+20x+4x-8-2x^2-10=24\to\\\\-2x^2+24x-40=0\,\,[\div (-2)]\to\\\\x^2-12x+20=0\to\text{Bhaskara}\to\\\\x=\dfrac{12\pm\sqrt{(-12)^2-4.1.20}}{2.1}\to\\\\x=\dfrac{12\pm\sqrt{64}}{2}\to\dfrac{12\pm 8}{2}\to\\\\x_{1}=\dfrac{12-8}{2}\to\boxed{x_{1}=2}\checkmark\\\\\text{ou}\\\\x_{2}=\dfrac{12+8}{2}\to\boxed{x_{2}=10}\checkmark$

É isso!! :)