- 5X - 2Y = 2 ( * 2 )
- 10X - 4Y = 4
2X + 4Y = 1
- 8X = 5
X = ( - 0.625)
2 * ( - 0.625) + 4Y = 1
- 1.25 + 4Y = 1
4Y = 2.25
Y = 0.5625
ОТВЕТ: X = ( -0.625) ; Y = 0.5625
(9x⁶ - 4x³) - (x³ - 9) - (8x⁶ - 5x³) = x⁶ + 9
9x⁶ - 4x³ - x³ + 9 - 8x⁶ + 5x³ = x⁶ + 9
9x⁶ - 8x⁶ - 5x³ + 5x³ + 9 = x⁶ + 9
x⁶ + 9 = x⁶ + 9
Тождество доказано
4 sin(arcsin 1/3+arccos 1/3)=4sin(pi/2)=4*1=4