Question

(-20)*(+1)*(-2)*(-3)*(-4)=
(-1/2)*2*(-1/3)*3*(-1/4)*4=
(-0,1)*10*(-0,2)*5*9-0,25)*4=

Answer 1

(-20)*(+1)*(-2)*(-3)*(-4)=20*1*2*3*4=20*24=480
(-1/2)*2*(-1/3)*3*(-1/4)*4= - (1/2*2*1/3*3*1/4*4)= - 1
(-0,1)*10*(-0,2)*5*9*(-0,25)*4= - (0,1*10*0,2*5*9*0,25*4)= - (1*1*9*1)= - 9