(1)0.125×4.78×80 =0.125×80×4.78=10×4.78=47.8; (2)(0.4+40)×2.5 =0.4×2.5+40×2.5=1+100=101; (3)6.9×87+6.9×14-6.9=6.9×(87+14-1)=6.9×100=690.