2x + 3x = 5x 3x + 7x = 10a + 3a = 17b-9b = 38y-20y = 81c-60c + 4c = 61*5=5*(60 + 1) = 5*60+5*1 = 300+5= 72*6 = 43*7= 299 * 3 = 3*(300- 1) = 3*300-3*1 = 900-3 = 398*4= 597*3 = 3(x+2) = 3*x + 3*2 = 5(y + 3) = 11(2-a) = 4(7a-x) = a(12-b) = 8(2a + x - 10) = 24 * 13 + 24 * 87 = 24*(13+87) = 24 * 100 = 67*15 +33 * 15 = 72*28-62 * 28 = 154*30-30 * 124 = 687*25-25 * 487 = 5x + 3x = 64 8x = 64 X = 64:8 X = 8 3y + 8y = 55 7a + 5a-12 = 132 12a-12=132 12a = 132 + 12 12a = 144 a = 144:12 a = 12 9c+6c-10 = 20

3x + 7x = 10x

10a + 3a = 13a

17b - 9b = 8b

38y - 20y = 18y

81c - 60c + 4c = 25c

61 * 5 = 5 * (60 + 1) = 5 * 60 + 5 * 1 = 300 + 5 = 305

72 * 6 = 432

43 * 7 = 301

299 * 3 = 3 * (300 - 1) = 3 * 300 - 3 * 1 = 900 - 3 = 897

398 * 4 = 1592

597 * 3 = 1791

3(x + 2) = 3 * x + 3 * 2 = 3x + 6

5(y + 3) = 5y + 15

11(2 - a) = 22 - 11a

4(7a - x) = 28a - 4x

a(12 - b) = 12a - ab

8(2a + x - 10) = 16a + 8x - 80

24 * 13 + 24 * 87 = 24 * (13 + 87) = 24 * 100 = 2400

67 * 15 + 33 * 15 = 1005 + 495 = 1500

72 * 28 - 62 * 28 = 2016 - 1736 = 280

154 * 30 - 30 * 124 = 4620 - 3720 = 900

687 * 25 - 25 * 487 = 17175 - 12175 = 5000

5x + 3x = 64

8x = 64

x = 64:8

x = 8

3y + 8y = 55

11y = 55

y = 55 : 11

y = 5

7a + 5a - 12 = 132

12a - 12 = 132

12a = 132 + 12

12a = 144

a = 144 : 12

a = 12

9c + 6c - 10 = 20

15c - 10 = 20

15c = 20 + 10

15c = 30

c = 30 : 15

c = 2