ВАРИАНТ 21 1. 11x-3=6x + 12 2. 6(2x-5)-4-2 3. 6x-1=3x+5(4x-7) 4. 4(6x+5)-5(7x-4) = x 5. 4x-6(3x+8) -5(2x-7) = 35 6. 7(2x-3)+1 = 2(7x-10) ВАРИАНТ 26 1.-5x-22=-8x-4 2. 7(4x-3)-2x = 5 3. 4x+5= 2x + 3(5x+6) 4. 25-4(4x-3) =3(5x+2) 5. 7x-2(5x-3)-4(2-3x) = 1 6. 9(2x-1)+2=2(9x-3)-1 ВАРИАНТ 31 1.-4x-11=-5x-12 2. 5(2x-1)+x=6 3. 3x+11=5x +7(3x-5) 4. 3x-4(5x+2) =3(7x-2) 5. 17-2(3x-5)-5(4x-1) = 6x 6. 11x+3(x-3)=-8x-9 ВАРИАНТ 36 1. 8x+12= 5x + 3 2. 3(2x+1)+7=4 3. 6+3(5x-7) = 4x +7 4. 3(7x-4)-4(6x + 5) = x 5. 3x-5(2x+3) -6(5x-4)=-28 6. 3(x+21)+2(x-4)=5(x+11)

ВАРИАНТ 21

1. 11x - 3 = 6x + 12

   11x - 6x = 12 + 3

   5x = 15

   x = 3

2. 6(2x - 5) - 4 = 2

   12x - 30 - 4 = 2

   12x = 36

   x = 3

3. 6x - 1 = 3x + 5(4x - 7)

   6x - 1 = 3x + 20x - 35

   6x - 23x = -35 + 1

   -17x = -34

   x = 2

4. 4(6x + 5) - 5(7x - 4) = x

   24x + 20 - 35x + 20 = x

   -11x - x = -40

   -12x = -40

   x = 10/3

5. 4x - 6(3x + 8) - 5(2x - 7) = 35

   4x - 18x - 48 - 10x + 35 = 35

   -24x = 48

   x = -2

6. 7(2x - 3) + 1 = 2(7x - 10)

   14x - 21 + 1 = 14x - 20

   14x - 14x = 20

   0 = 0

   x - любое число

ВАРИАНТ 26

1. -5x - 22 = -8x - 4

   3x = 18

   x = 6

2. 7(4x - 3) - 2x = 5

   28x - 21 - 2x = 5

   26x = 26

   x = 1

3. 4x + 5 = 2x + 3(5x + 6)

   4x + 5 = 2x + 15x + 18

   -13x = 13

   x = -1

4. 25 - 4(4x - 3) = 3(5x + 2)

   25 - 16x + 12 = 15x + 6

   -31x = -31

   x = 1

5. 7x - 2(5x - 3) - 4(2 - 3x) = 1

   7x - 10x + 6 - 8 + 12x = 1

   9x = 3

   x = 1/3

6. 9(2x - 1) + 2 = 2(9x - 3) - 1

   18x - 9 + 2 = 18x - 6 - 1

   18x - 18x = 4

   0 = 4

   нет решения

ВАРИАНТ 31

1. -4x - 11 = -5x - 12

   x = -1

2. 5(2x - 1) + x = 6

   10x - 5 + x = 6

   11x = 11

   x = 1

3. 3x + 11 = 5x + 7(3x - 5)

   3x + 11 = 5x + 21x - 35

   -23x = -46

   x = 2

4. 3x - 4(5x + 2) = 3(7x - 2)

   3x - 20x - 8 = 21x - 6

   -38x = 2

   x = -1/19

5. 17 - 2(3x - 5) - 5(4x - 1) = 6x

   17 - 6x + 10 - 20x + 5 = 6x

   -32x = -32

   x = 1

6. -11x + 3(x - 3) = -8x - 9

   -11x + 3x - 9 = -8x - 9

   -8x + 8x = 0

   0 = 0

   x - любое число

ВАРИАНТ 36

1. 8x + 12 = 5x + 3

   3x = -9

   x = -3

2. 3(2x + 1) + 7 = 4

   6x + 3 + 7 = 4

   6x = -6

   x = -1

3. 6 + 3(5x - 7) = 4x + 7

   6 + 15x - 21 = 4x + 7

   11x = 22

   x = 2

4. 3(7x - 4) - 4(6x + 5) = x

   21x - 12 - 24x - 20 = x

   -3x - 32 = x

   -4x = 32

   x = -8

5. 3x - 5(2x + 3) - 6(5x - 4) = -28

   3x - 10x - 15 - 30x + 24 = -28

   -37x = -37

   x = 1

6. 3(x + 21) + 2(x - 4) = 5(x + 11)

   3x + 63 + 2x - 8 = 5x + 55

   5x + 55 = 5x + 55

   0 = 0

   x - любое число

Проверка за 10 секунд: Убедись, что правильно раскрыты скобки и перенесены слагаемые с изменением знака. Пересчитай арифметику.

Читерский прием: Если уравнение имеет вид 0 = 0, значит, x - любое число. Если получилось, что 0 = числу, то решения нет.