4. 1/2*130/100*260=169 - С
5. 35+(87-х)=49; х=35+87-49;х=73 - Д
6. 912=2*2*2*2*3*19=2
*3*19 - Е
7.90*20/100=18г соли;х*9/100=18; х=18*100/9=200, 200-90=110 - Е
8.(96-36-30)/96*100= 31,25% -Е
9. 38*4=152° -В
10. 180-67=113° - Е
11.53*59*61= 190747 - Д
12. 9(0),1(00),11(0)=0000 - Е
13.1,372*100=137,2 - А
14. 1 2/5 /5+0,175*2/7=7/5*1/5+175/1000*2/7=7/25+25*7*2/(7*25*2*20)=7/25+1/20=(7*4+1*5)/100=33/100- свой вариант))
15.2/3+36:(11,8+1/5)=2/3+36/12=2/3+3=3 2/3 - В