Question

va rog a- de la ex 18​

Answer 1

$(x+1)^{2} + (x+2)^{2} - 2(x-3)^{2} = 5x^{2}$

$x^{2} + 2x + 1 + x^{2} + 4x + 4 - 2x^{2} +12x -18 = 5x^{2}$

$18x - 13 = 5x^{2} \iff 5x^{2} - 18x + 13 = 0$

$5x^{2} - 5x - 13x + 13 = 0 \Rightarrow 5x(x - 1) - 13(x - 1) = 0$

$(5x - 13)(x - 1) = 0$

$\implies x_{1} = \dfrac{13}{5} ; \ x_{2} = 1$