3 х 3 = 9 или 3 + 3 + 3 = 9
-5 (y-4)+2 (y+5)
-5y+20+2 y+10= -3y+30
1) -у+1,45=3,2
-у=3,2-1,45
-у=1,75
у=-1,75
2) -(-(-(-(-а))))+8=-(-8,4)
-а+8=8,4
-а=8,4-8
-а=0,4
а=-0,4
А)1/8+х=3/5
х=3/5-1/8
х=19/40
б)5/4-b=1/6
<span>b=5/4-1/6
</span><span>b=1 целая 1/2
</span>
в)d+1/3=5/12
<span>d=5/12-1/3
</span><span>d=-1/4
</span>
г)у-2/9=7/18
<span>у=7/18+2/9
</span><span>у=11/18</span>
1-3/5=2/5 во второй день
30=2/5х
х=30/2*5=75