a)(5*2)*(13*7)=919
б)(5*4)*(6*5)=600
в)(2*5)*(2*5)*7=700
г)(5*2*9)*(5*4)=1800
д)(125*4)*(25*8)=100000
е)(5*2*(5*2)*(5*2)*(5*2)*6=60000