x/2.4=15/0.87q)d-n;M)\'[/~'a:W4?
算式：提示.v8_'B(Q2m/~;V7x7q)d-n;M)\'[/~'a:W4?
x=1u'R3p;Z'\1Q7q)d-n;M)\'[/~'a:W4?