(49*b^2-4)*(1/(7*b-2)-1/(7*b+2))-b+15
(16*b/a-16*a/b)-1/4*a+4*b
(x+1)/x^2+2*x+1/x-1
(49*a^2-9)*(1/(7*a-3)-1/(7*a+3))
上述示例还包含:
可进行以下运算