Question

(+2又8/31)x(-1又2/7)x(+2又1/15)x(-4又1/2)

Answer 1

(+2又8/31)x(-1又2/7)x(+2又1/15)x(-4又1/2)

=70/31*(-9/7)*31/15*(-9/2)

=(70*9*31*9)/(31*7*15*2)

=(7*10*9*9)/(7*15*2)

=(10*9*9)/(15*2)

=(2*5*3*3*9)/(3*5*2)

=27