1) 4(x-3)=x+6
2) 4-6(x+2)=3-5x
3) (5x+8)-(8x+14)=9
4) 2,7+3y=9(y-2,1)
5)0,3(8-3y)=3,2-0,8(y-7)
6
4,3/5
72
Mejora
хорошист
152 ответов
45.3 тыс. пользователей, получивших
4(x-3)=x+6
4x-12=x+6
4x-x=6+12
3x=18
x=18:3
x=6
4-6(x+2)=3-5x
4-6x-12=3-5x
-8-6x=3-5x
-6x+5x=3+8
-x=11
x=-11
(5x+8)-(8x+14)=9
5x+8-8x-14=9
-3x-6=9
-3x=6+9
-3x=15
x=- 5
2,7+3y=9(y-2,1)
2.7+3y=9y-18.9
3y-9y=-18.9-2.7
-6y=-21.6
y=3.6
0,3(8-3y)=3,2-0,8(y-7)
2.4-0.9y=3.2-0.8y+5.6
-0.9y+0.8y=8.8-2.4
-0.1y=6.4
y=-64
5,6(1,3x-1,5)=3x+3 1/3
7,28x-8,4=3x+3 1/3
7.28x-3x=3 1/3 + 8.4
4.28x=10/3+8.4|*3
12,84x=10+25,2
x=2 952/1284 = 2 238 / 321
1) 4(x-3)=x+6
2) 4-6(x+2)=3-5x
3) (5x+8)-(8x+14)=9
4) 2,7+3y=9(y-2,1)
5)0,3(8-3y)=3,2-0,8(y-7)
6
4,3/5
72
Mejora
хорошист
152 ответов
45.3 тыс. пользователей, получивших
4(x-3)=x+6
4x-12=x+6
4x-x=6+12
3x=18
x=18:3
x=6
4-6(x+2)=3-5x
4-6x-12=3-5x
-8-6x=3-5x
-6x+5x=3+8
-x=11
x=-11
(5x+8)-(8x+14)=9
5x+8-8x-14=9
-3x-6=9
-3x=6+9
-3x=15
x=- 5
2,7+3y=9(y-2,1)
2.7+3y=9y-18.9
3y-9y=-18.9-2.7
-6y=-21.6
y=3.6
0,3(8-3y)=3,2-0,8(y-7)
2.4-0.9y=3.2-0.8y+5.6
-0.9y+0.8y=8.8-2.4
-0.1y=6.4
y=-64
5,6(1,3x-1,5)=3x+3 1/3
7,28x-8,4=3x+3 1/3
7.28x-3x=3 1/3 + 8.4
4.28x=10/3+8.4|*3
12,84x=10+25,2
x=2 952/1284 = 2 238 / 321
1) x² - 6x + m = x² - 2 * 3 * x + 9 = (х - 3)², m = 9
2) x² + 16x + m = x² + 2 * 8 * x + 64 = (x + 8)², m = 64
3) x² - mx + 9 = x² - 2 * 3 * x + 9 = (x - 3)², m = 6
2. Решить уравнение
1) x² - 3x - 10 = 0
а = 1; b = -3; c = -10
D = b² - 4ac = (-3)² - 4 * 1 * (-10) = 9 + 40 = 49
x1 = - b + √D = - ( - 3) + √49 = 3 + 7 = 5
2a 2 * 1 2
x2 = - b - √D = - ( - 3) - √49 = 3 - 7 = -2
2a 2 * 1 2
ответ: -2; 5
2) 5x² - 7x - 6 = 0
а = 5; b = -7; c = -6
D = b² - 4ac = (-7)² - 4 * 5 * (-6) = 49 + 120 = 169
x1 = - b + √D = - ( - 7) + √149 = 7 + 13 = 2
2a 2 * 5 10
x2 = - b - √D = - ( - 7) - √149 = 7 - 13 = 0,6
2a 2 * 5 10
ответ: 0,6; 2