1. А) 0; 2. В) 31626; 3. А) -8; 4. 33 кв.см.; 5. 15
Пошаговое объяснение:
1. y(x) = (-2)*|x^2 - 9| + 20
y(3) = (-2)*|9 - 9| + 20 = 20
y(4) = (-2)*|16 - 9| + 20 = (-2)*7 + 20 = -14 + 20 = 6
y(5) = (-2)*|25 - 9| + 20 = (-2)*16 + 20 = -32 + 20 = -12
2. 354516=372*953; 35340=372*95; 31626=372*85+6; 29388=372*79
3. x^2 + 5x - 24 = 0
D = 5^2 - 4*(24) = 25 + 96 = 121 = 11^2
x1 = (-5 - 11)/2 = -16/2 = -8; x2 = (-5+11)/2 = 6/2 = 3
4. Основания трапеции а и 2а см, боковые b > 2 см, высота h = 2 см.
периметр P = a + 2a + 2b = 3a + 2b = 40 см.
a = (40 - 2b)/3 = 10 + (10 - 2b)/3
При b = 3,5 см будет a = 10 + (10 - 2*3,5)/3 = 10 + (10 - 7)/3 = 11 см.
Основания a = 11 см, 2a = 22 см, площадь
S = (a + 2a)*h/2 = (11 + 22)*2/2 = 33 кв.см.
5. 2(a-5) = 2 + 6(3-b)
2a - 10 = 2 + 18 - 6b
2a = 30 - 6b
a = 15 - 3b
Значение выражения
a + 3b = 15 - 3b + 3b = 15
24/11х=7/4+5/16
24/11х=28/16+5/16
24/11х=33/16
х=33/16:24/11=33/16*24/11=3/16*24/1=3/2*3=9/2=4 1/2=4,5
2) 4 2/9x +3 5/14 = 6 11/21
38/9х=137/21-47/14
38/9х=274/42-141/42
38/9х=133/42
х=133/42:38/9=133/42*9/38=133/14*3/38=3,5/14*3=10,5/14=105/140=3/4=0,75
3) 11/18 - 14/27x = 5/12
-14/27х=5/12-11/18
-14/27х=15/36-22/36
-14/27х=-7/36
х=7/36:14/27=7/36*27/14=1/36*27/2=1/4*3/2=3/8=0,375
4) 1/3x + 1/4x + 1/5x =94/75
20/60х+15/60х+12/60х=94/75
47/60х=94/75
х=94/75:47/60=94/75*60/47=2/75*60/1=2/3*4=8/3=2 1/3
5) 4 1/2 : X +1 3/4 = 3 19/28
9/2:х=103/28-7/4
9/(2х)=103/28-49/28
9/(2х)=54/28 умножим на 2
9/х=54/14
9/х=27/7
х=9:27/7
х=9*7/27=1*7/3=7/3=2 1/3
6) 3 2/3 : (X- 2 4/15) = 3 5/13
11/3 : (X- 34/15) = 44/13
X- 34/15=11/3:44/13
X- 34/15=11/3*13/44
X- 34/15=1/3*13/4
X- 34/15=13/12
Х=13/12+34/15
Х=65/60+136/60
Х=201/60=3 21/60