)))))))))))))))))))))))))))))))))))
(5xy^2-3x^3+2x^2y)(2x^2-xy-4y^2)=10x^3y^2-5x^2y^3-20xy^4-6x^5+3x^4y+12x^3y^2+4x^4y-2x^3y^2-8x^2y^3=20x^3y^2-13x^2y^3-20xy^4-6x^5+7x^4y
(1 1/9 * 0.27 - 3 1/3 * 0.15) - 1500 (-0.1)^3= (10/9 * 27/100 - 10/3 * 15/100) + 1500*0.001= (3/10 -5/10) +1.5= -0.2+1.5=1.3
Решение
1) а) 17 + (z² - 1)² = z⁴
17 + z⁴ - 2z² + 1 - z⁴ = 0
2z² = 18
z² = 9
z₁ = - 3
z₂ = 3
б) 4x² + 4x + 1 = 0
D = 16 - 4*4*1 = 0
x = - 4/8
x = = - 1/2
или
(2x + 1)² = 0
1 + 2x = 0
2x = - 1
x = - 1/2
2) а) (x - 1)(x² + x + 1) - x³ = x
x³ - 1 - x³ - x = 0
- x = 1
x = - 1
б) x² - 6x + 8 = 0
x₁ = 2
x₂ = 4
4) a/[(1 + a + a²)(1 - a)] = a/(1 - a³)