（21/25+14/15）×5/7+1/3*t.Q6D:C;y*Z)k2t:w
算式：提示+_.B0F;x3f(O*t.Q6D:C;y*Z)k2t:w
=15N+R.I/j,t.a*t.Q6D:C;y*Z)k2t:w