Điền vào chỗ trống:

a) 14 + 27 + 36 = (14 + 36) + 27 = 50 + 27 = 77

b) 4.15.25.6 = (4.25).(15.6) = 100.90 = 9000

c) 5.125.2.4 = (5.4).(125.4) = 10.500 = 5000

d) 176 + 483 + 24 + 117 = (176+24) + (483 + 117) = 200 + 600 = 800

e) 12.41 + 12.59 = 12.(41+59) = 12.100 = 1200

f) 17.32 + 43.17 + 17.25 = 17.(32+43+25) = 17.100 = 1700

g) 2 + 4 + 6 + … + 22 = 2.(1 + 2 + 3 + … + 11) = 2.(12.11:2) = 2.66 = 132

a) x – 12 = 14

x = 14 +12

x = 26

b) 2x – 13 = 3.17

2x = 51 + 13

2x = 64

x = 64 : 2

x = 32

c) x – 43 = 2.18

x = 36 +43

x = 79

d) (x – 14).39 = 0

x – 14 = 0

x = 14

e) (13 – x).28 = 28

13 – x = 1

13 – x = 1

x = 13 – 1

x = 12

f) 22.(35 – x) = 22

35 – x = 1

x = 35 – 1

x = 34

g) x – 24 : 2 = 18

x – 12 = 18

x = 39

h) 400 + (275 – x) = 570

275 – x = 570 – 400

275 – x = 170

x = 275 – 170

x = 105