Question

Решите уравнение (5х + 2) = (5x - 3)(4x + 1). CРОЧНО!!!

Answer 1

$(5x + 2) = (5x - 3)(4x + 1)\\\\5x+2=20x^2-12x+5x-3\\\\20x^2-12x-5=0\\\\D=144+400=544$

$\sqrt{D}=\sqrt{544}=\sqrt{16\cdot 34} =4\sqrt{34}$

$x_{1}=\frac{12-4\sqrt{34}}{40}; x_{2}=\frac{12+4\sqrt{34}}{40}$

О т в е т.

$x_{1}=\frac{3-\sqrt{34}}{10}; x_{2}=\frac{3+\sqrt{34}}{10}$