42÷(2.4-1)×(1+2.4)=42÷1.4×3.4=30×3.4=102(页)方程:解:设没看完的有x页2.4x-x=421.4x=42x=30这本书有:30+30×2.4=102(页)
42x(2.4+1)/(2.4-1)=42x34/14=102(页)