(5x²-3)-(2x+5) = 5x²
5x²-3-2x-5 = 5x² |+(2x-5x²)
5x²-5x²-8+2x-2x = 5x²-5x²+2x
2x = -8 |:2
x = -4
ответ: x = -4.
(5x²-3)-(2x+5) = 5x²
5x²-3-2x-5 = 5x² |+(2x-5x²)
5x²-5x²-8+2x-2x = 5x²-5x²+2x
2x = -8 |:2
x = -4
ответ: x = -4.