1)34*(-4)= - 136
2)-7,2*(-7)=50,4
3)-3 2/5*1 2/3= - 85
А)
3,6:4,2=6:Х;
36/10*10/42=6/Х;
36/42=6/х;
36/42=36/6х;
х=42/6=7.
б)15:10=X:40;
1,5=х/40;
х=40*1,5=60;
в)3:X=3/8:1/4;
3/х=3/8*4/1;
3/х=3/2;
х=2;
г)X:1 1/3 =6:4;
х/(4/3)=6/4;
х*3/4=6/4;
х*3=6;
х=2.
<span>д)X:3.86=2.5:2 1/2;
х/386/100=25/5/2;
100х/386=50/5=10;
100х=3860;
х=38,6.</span>
А) 2 1/2=5/2
5/2 * 2/(-75) = - 5/75 = - 1/15
г) 4 1/2 = 9/2
-5/9 * 9/2 = - 5/2 = - 2 1/2
ж) 2 1/5 = 11/5
-3/4 * 11/5 = - 33/20
А)315\320=63\64
б)48\124=12\31
в)360\420=6\7
г)312\390=52\65