139/2=69,5;
(69,5+0,5)+(69,5-0,5)=70+69=139.
26176:(y×56-46856)=409
y×56-46856=26176:409
y×56-46856=64
y×56 =64 + 46856
y×56 = <span>46920
</span>y = <span>46920 : 56
</span>у = 837,8
---------------------------------
(y+3698):507=630
y+3698=630 х 507
y+3698=319410
у = 319410 - 3698
у = 319041
--------------------------------------
42172-5×x=7152
-5×x=7152- <span>42172
</span>-5х = - 35020
х = - 35020: (-5)
х = 7004
1. 90-35-23=32
2. 90-(35+23)=90-58=32