1) нет х и у то решыть не могу
2) -0,8х-1 0,8х-1 при х=6
(-0,8*6) -1 (0,8*6) -1
-4,8 -1 = -5,8 3,8
-5,8<3,8
3) a) 2x -3y -11x + 8y = 5y - 9x
б) 5(2a+1) -3 = 10a +5-3 =10a +2
в) 14x - (x - 1) + (2x + 6) = 14x - x + 1 + 2x + 6 = 15x + 7
4) нет значени а
5) 1. 2*60=120
2. 200-120=80
3. 80/2=40
6) 3x -(5x - ( 3x -1)
3x - (5x - 3x + 1)
3x - 5x + 3x -1
a) (x²-1)(x-2)(x+3)≤ 0
(x-1)(x+1)(x-2)(x+3)≤0
-3-112
+ - + - +
x∈[-3; -1]∪[1; 2]
б) (x²-25)(x-2)(x-4)≥0
(x-5)(x+5)(x-2)(x-4)≥0
-5245
+ - + - +
x∈(-∞; -5] ∪[2; 4]∪[5; +∞)
в) (x²-2x-8)(x+5)≤ 0
(x²-4x+2x-8)(x+5)≤ 0
(x(x-4)+2(x-4))(x+5)≤ 0
(x+2)(x-4)(x+5)≤0
-5-24
- + - +
x∈(-∞; -5] ∪[2; 4]
г) (x²+2x-15)(x-1)≥ 0
(x²-3x+5x-15)(x-1)≥ 0
(x(x-3)+5(x-3))(x-1)≥ 0
(x-3)(x+5)(x-1)≥0
-513
- + - +
x∈[-5; 1]∪[3; +∞)
д) (x² -16)(x²+2x-8)(x-2)≤ 0
(x-4)(x+4)(x-2)(x+4)≤0
(x-4)(x+4)²(x-2)≤0
-424
+ + - +
x∈[2; 4]
е) (x²-9)(x²+x-6)(x+5)≥ 0
(x-3)(x+3)(x-1)(x+5)(x+5)≥0
(x-3)(x+3)(x-1)(x+5)²≥0
-5-313
- - + - +
x∈[-3; 1]∪[3; +∞)
x(x^2-8x+15)/(x^2-7x+12) * 1/(x-4) ≤ 0
x(x-3)(x-5)/(x-3)(x-4) * 1/(x-4) ≤ 0
x(x-5)/(x-4)^2 ≤ 0 (! x не равен 3!)
+ - - - +
[0](3)(4)[5]> x
x = [0;3)U(3;4)U(4;5]
0+1+2+5=3+5=8