Question

a) (3/4 - 1/5) : 1/2

b) 3,2 : (0,8- 2/5)

c) 2/3 * (1/2 - 1/6)

d) 4,8 + 1/3 * (1,2 - 0,6)

e) (1 - 7/9) * (5,2 - 0,7)

f) 123 : 10 + 0,2 * 6,1

g) (6,5 - 4,7) : (4 - 2 i 1/5)

h) (1,5 - 1 i 1/3) * 2 i 2/5 - 0,1

i) (6,25 - 2 i 1/2) : 2 i 1/7 - 1

Answer 1

a) (3/4 - 1/5) : 1/2 = (15/20-4/20) * 20 = 11/20 * 20 = 11

 

b) 3,2 : (0,8 - 2/5) = 3,2:(0,8-0,4) = 3,2:0,4 = 8

 

c) 2/3 * (1/2 - 1/6) = 2/3 * (3/6-1/6) = 2/3 * 2/6 = 4/18 = 2/9

 

d) 4,8 + 1/3 * (1,2 - 0,6) = 4,8+1/3 * 0,6 = 48/10 + 1/3 *6/10 = 48/10 + 6/30 = 48/10+2/10 = 50/10 = 5

 

e) (1 - 7/9) * (5,2 - 0,7) = 2/9 * 4,5 = 2/9 *45/10 = 90/90 = 1

 

f) 123 : 10 + 0,2 * 6,1 = 12,3+1,22 = 13,52

 

g) (6,5 - 4,7) : (4 - 2 i 1/5) = 1,8 : (4-2,2) = 1,8 : 1,8 = 1

 

h) (1,5 - 1 i 1/3) * 2 i 2/5 - 0,1 = (15/10-4/3) * 12/5-1/10 = (45/30-40/30) *12/5-1/10 = 5/30*12/5-1/10 = 60/150-1/10 = 2/5-1/10 = 4/10-1/10 = 3/10

 

i) (6,25 - 2 i 1/2) : 2 i 1/7 - 1 = (6,25-2,5) : 15/7-1 = 3,75 : 15/7 -1 = 15/4 * 7/15 - 1 = 7/4 - 1 = 1 3/4 - 1 = 3/4