Question

Решите, плиз. фото ниже

Answer 1

$(x-5)^2+x(x-5)-x-4x=-9\\\\x^2-10x+25+x^2-5x-5x=-9\\\\2x^2-20x+34=0\; |:2\\\\x^2-10x+17=0\\\\D/4=5^2-17=8\\\\x_1=5-\sqrt8=5-2\sqrt2\\\\x_2=5+2\sqrt2$