Х²-7Х+3Х-21-20Х+8Х²=9Х²-24Х-21
у²-6у+2у-12+у²-4у+3у-12=2у²+3у
3z²+z-9z+3-8z²+2z-12z+3=-5z²-18z+6
14a²+8ab-21ab-12b²-14a²+21ab-4ab+6b²=6b²+12ab
m5+2m³n-3m²n-6n²-4m5-28m³n=-3m5-26m²n-6n²
Объяснение:
Х²-7Х+3Х-21-20Х+8Х²=9Х²-24Х-21
у²-6у+2у-12+у²-4у+3у-12=2у²+3у
3z²+z-9z+3-8z²+2z-12z+3=-5z²-18z+6
14a²+8ab-21ab-12b²-14a²+21ab-4ab+6b²=6b²+12ab
m5+2m³n-3m²n-6n²-4m5-28m³n=-3m5-26m²n-6n²
Объяснение: