12.5：2=7.5：x:x:s4z;C1O+j6b(Y
算式：提示)i/h.P(R4[:o*B4y,f3\5]:x:s4z;C1O+j6b(Y
x=-h;U5C4U*L9k2d:x:s4z;C1O+j6b(Y