y³-3y²+9y+3y²-9y+27-y³+6y = 0
6y+27 = 0
6y = -27
y = -27/6 = -9/2
y = -4.5
(3m - 2n²)³ = (3m)³ - 3 * (3m)² * 2n² + 3 * 3m * ( 2n²)² - (2n²)³ =
= 27m³ - 54m²n² + 12mn⁴ - 8n⁶
(3x - 8y)² = (3x)² - 2 * 3x * 8y + (8y)² = 9x² - 48xy + 64y²
(3a² + 2c)² = (3a²)² + 2 * 3a² * 2c + (2c)² = 9a⁴ + 12a²c + 4c²
2+3(x+5y)=-(2x+3y)⇒2+3x+15y+2x+3y=0⇒5x+18y+2=0
3x+4y=-8⇒y=-2-0,75x
5x-36-13,5x+2=0
8,5x=-34
x=-34:8,5=-4
y=-2-0,75*(-4)=-2+3=1