Question

Va rog ajutați-mă doar 6 si 7

Answer 1

Răspuns:

Explicație pas cu pas:

6.a.  0,5-1/2(3/4-0,25)=

       5/10-1/2(3/4-25/100)=

      5/10-1/2(3/4-1/4)=

      5/10-1/2x(3-1)/4=

       5/10-1/2x2/4=b.  

       5/10-1/4=

       (10-5)20=

        5/20=1/4

b.   0,75-0,75x(19/10-1,5)=

      75/100-75/100x(19/10-15/10)=

      3/4-3/4x(19-15)/10=

      3/4-3/4x4/10=

       3/4-3/10=

       (15-6)/20=9/20

c.   (1/3+0,25)(1+5/7)=

      (1/3+25/100)((7/5)/7=

     (  1/3+1/4)x12/7=

      (4+3)/12x12/7=

      7/12x12/7=1

d.   2/5(0,5+0,5x1/3)=

       2/5(5/10+5/10x1/3)=

      2/5(5/10+5/30)=

    2/5x(15+5)/30=

       2/5x20/30=4/15

7.a.  3,75+(0,5-1/5+0,35)x10=

      375/100+(5/10-1/5+35/100)x10=

      15/4+(5/10-1/5+7/20)x10=

    15/4+((10-4+7)/20x10=

      15/4+13/2=

      (15+26)/4=41/4

b.   1/2+0,75+(0,1+1/2-0,5+0,9)÷10=

     1/2+75/100+(1/10+1/2-5/10+9/10)÷10=

      1/2+3/4+((1+5-5+9)/10x1/10=

      1/2+3/4+10/10x1/10=

      1/2+3/4+1/10=

      (10+15+2)/20=

      27/20

c.   (0,2+1/2+0,02x10)[(0,35+8/20)x10-65÷10]=

     (2/10+1/2+2/100x10)÷[(35/100+8/20)x10-65/10]=

     (2/10+1/2+1/50x10)÷[(7/20+8/20)x10-65/10]=

     ÷(2/10+1/2+1/5)÷[(7+8)/20x10-13/2]=

     (2+5+2)/10÷(15/20x10-13/2)=

     9/10÷(15/2-13/2)=

      9/10÷2/2=

      9/10x2/2=9/10