Real Math talk good practice examples of mathematics | Page 5

teams have got individual tasks ( 5 min)
(solve inequalities)
(1)
1)  2 x  4
1
2) x  3  0
2
30  5 x  18  7 x
3) 2 x  5  4  3 ( x  2 )
5 x  5  3 ( 15  x )
(2)
1) -3x > 0 (3)
1)  4 x   16
2) 2 . 5 x  1  x  2 2)
3) 11  5 x  1  4 ( 2  x ) 3)
(4)
1) 3 x  9
2) x  4  x  7
3) 2 x  ( x  4 )  6
7 x  4 ( x  6 )  30 (5)
1)  11 x  33
2) 9 x  28  x  4
3) 5 x  1  4 ( x  2 )
(7)
1)  2 x   6
2) 8 x  20  5 x  14
3) 6 x  ( x  6 )  4  x (8)
1) 6 x   12
2)  4 x  11   x  13
3) 7 x  2  5 ( x  2 )
4) task to captains
say integer numbers, which belongs to the intervals.
I
II
  2 ; 5 
  3 ; 4 
(6)
1)  6 x  42
2) 2 x  4  x  6
3)
III
  4 ; 2 
5) task
the captains check opponents homework and assess them
Summarize results
2nd round (team winner)
The members of the team-winner answer in turn, correct and give correct answers (if they failed)
only the members from another team. They use sound sign if they want to answer. Each task lasts 1
min.:
2
3
1) say 4 numbers, existing among  5
and  5
10
10
2) continue a notion:
2) any term of inequality can be transfered......................................................................
3) inequality can be multiplied or divided from any numbers except for zero..........
4) from two negative numbers, a bigger one is, which ...............................................................
5) find a mistake :
7  3 x  2 x  2
 5 x   5
x  1
1
 
x    1 ;  
6) find a mistake: