Question

2×7^log7x=x2-3 спростити вираз

Answer 1

$2*7^{log_7X}=x^2-3\\a^{log_ab}=b\\2*x=x^2-3\\x^2-2x-3=0\\D^2= (-2)^2-4*(-3)=4+12=16, D=+-4\\x_1=\frac{2+4}{2}=3\\x_2=\frac{2-4}{2}=-1\\(x-3)(x+1)=0$