【(7/12-1/4)×2+2/3】÷1.5=【1/3×2+2/3】÷1.5=4/3×2/3=8/9
这个数是:{[(7/12)-1/4]×2+2/3}/1.5={[7/12-3/12]×2+2/3}*(2/3)={2/3+2/3}*(2/3)=4/3*2/3=8/9
设为x (1.5x-2/3)/2+1/4=7/12 两边乘以12 6(1.5x-2/3)+3=7 9x-4+3=7 x=8/9