(90-6•7):8•148-888+(3+21:3):10•888=

(90-6×7):8×148-888+(3+21:3):10×888=
(90-42):8×148-888+(3+7):10×888=
48:8×148-888+10:10×888=
6×148-888+1×888=
888-888+888=
0+888=888