4х²+12х-5х-15=4х²+9-12х 4х²+12х-5х-15-4х²-9+12х=0
19х=24х=24/19= 1 5/19
4x²+7x-5x-15=2x²-12x+9
4x²+7x-5x-15-2x²+12x-9=0
2x²+14x-24=0/:2
x²+7x-12=0
4х²+12х-5х-15=4х²+9-12х
4х²+12х-5х-15-4х²-9+12х=0
19х=24
х=24/19= 1 5/19
4x²+7x-5x-15=2x²-12x+9
4x²+7x-5x-15-2x²+12x-9=0
2x²+14x-24=0/:2
x²+7x-12=0