Question

Решите неравенство (5x-2)²-15> (4x-1)²+9x² и (у+3)(у-+4)²≥5-13у ))

Answer 1

$(5x-2)^2-15(4x-1)^2+9x^2 \\ 25x^2-20x+4-1516x^2-8x+1+9x^2 \\ 4-15-112x \\ x$

$(y+3)(y-9)-(y+4)^2 \geq 5-13y \\ y^2-9y+3y-27-y^2+8y+16 \geq 5-13y \\ 2y-11 \geq 5-13y \\ 15y \geq 16 \\ y \geq \frac{16}{15}$