Yoplait ejerciceos

1. x + 4 = 28

x = 24

2. y - 6.5 = 31

y = 37.5

3. 8z = 40 + 3z

8z -3z = 40

5z = 40

z = 8

4. 10x = - 5x + 60

10x + 5x = 60

15x = 60

x = 4

5. - 15y + 3 = - 36 - 18y

-15y +18y = -36 – 3

3y = -33

y = -11

6. 2x + 4 + (3x - 4) = 3x + 12

2x + 4 + 3x – 4 = 3x + 12

2x +3x -3x = -4 +4 +12

2x = 12

x = 6

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

12x + 8 – 8 = 10x + 15 + 5

12x  –10x = 20

2x = 20

x = 10

8. 15x - 40 - 5x - 20 = 0

15x – 5x = 40 + 20

10x = 60

x = 6

9. 16 - ( - 2x - 4) - (5x - 3x + 2) = - 4x - ( - 8x + 2)

16 + 2x + 4 +5x +3x +2 = -4x +8x -2

2x +5x +3x +4x -8x = -16 -4 -2 -2

6x = -24

x = -4

10. - (7x - 2 + 12) + ( - 5x - 3x + 4) = - ( - x + 7) - (6x - 4 - 7)

-7x +2 -12 -5x -3x +4 = +x -7 -6x +4 +7

-7x -5x -3x –x +6x = -2 +12 -4 -7 +4 +7

-10x = 10

x = -1

11. - 18 - [ 3(x + 2) + 4] = 21 - [ 6( - 2x - 2) + 1]

-18 – [3x +6 +4] = 21 – [-12x -12 +1]

-18 -3x -6 -4 = 21 +12x +12 -1

-3x -12x = 18 +6 +4 +21 +12 -1

 -15x = 60

x = -4