kalyabindima24 1)x*(1/2)=4; x=8дм
2) x*(2/5)=4; x=10дм
3) x*1(3/5)=x*(8/5)=4; x=2(1/2)дм
4) x*1(1/4)=x*(5/4)=4; x=3(1/5)дм