1.

1) 2,17+(3,2-0,17)=2,17+3,03=5,2

2)9,49-(1,5+0,99)=9,49-2,49=7

3) 13 7/9-(2,64+2 7/9)=11-2,64=8,36

4)6 7/8-(3,14-2 1/8)=4,75-3,14=1,61

2.

1) (1/2+1/3)x(1/5-1/4)=5/6x(-1/20)=-1/24

2)(2/7-3/4)x(2/13-1/2)=-13/28x(-9/26)=

=9/56

3)(0,3-1/20):(3/4-1,25)=(0,3-0,05):(0,75-1,25)=0,25:(-0,5)=-25/100x10/5=-0,5

4)(2,7-1/5):(1/2+4,5)=(2,7-0,2):5=2,5:5=0,5