6x-12y-20x+6y-15x+3=
11x-6y+3=
11*3/11 - 6*(-5/6)+ 3=
(Умножаем потом,ищем общий знаменатель)
744/66 + 451/66 +3=
1195/66 + 3=
18,1+3 = 21,3
1a) ax² - 4a = a(x² - 4) = a(x - 2)(x + 2)
б) 3m² - 12m + 12 = 3(m² - 4m + 4) = 3(m - 2)² = 3(m - 2)(m - 2)
в) 5x³ + 5y³ = 5(x³ + y³) = 5(x + y)(x² - xy + y²)
г) z⁴ - x¹² = (z²)² - (x⁶)² = (z² - x⁶)(z² + x⁶) = (z - x³)(z + x³)(z² + x⁶)
2a)6 - 3y + 18x - 9xy = (6 - 3y) + (18x - 9xy) = 3(2 - y) + 9x(2 - y) =
= (2 - y)(3 + 9x) = 3(2 - y)(1 + 3x)
б) a² - 4a + 4 - p² = (a² - 4a + 4) - p² = (a - 2)² - p² = (a - 2 - p)(a - 2 + p)
в) b² + b + c - c² = (b² - c²) + (b + c) = (b - c)(b + c) + (b + c) =
= (b + c)(b - c + 1)
3)3y³ - 12y² = 0
3y²(y - 4) = 0
3 ≠ 0
y² = 0 ⇒ y₁ = 0
y - 4 = 0 ⇒ y₂ = 4
Ответ : 0 ; 4
3/4+0.123=0.75+0.123=0.873
0.3-1/6=4/30=2/15
0.15*3/5=0.15*0.6=0.09
6/25:0.12=6/25:3/25=2
<span>2x^2-4x+x-2=0
2x(x-2)+x-2=0
2x(x-2)+(x-2)=0
(x-2)(2x+1)=0
</span>