Analysis: According to the meaning of the question, m≠0, and m0
Solution ①: The original equation can be changed to:
√[(7m^2+13)+9m]+√[(7m^2+13)-5m]=7m
order 7m^2+13=a(a≥13)
∴√(a+9m)+√(a-5m)=7m
∴√(a+9m)=7m-√(a-5m)
a+9m=49m ^2+a-5m-14m√(a-5m)
49m^2-14m=14m√(a-5m)
∵m≠0
∴7m-2=2√(a-5m)
∴49m^2- 28m+4=4a-20m
∴4a=49m^2-8m+4
∴4 (7m^2+13)=49m^2-8m+4
∴21m^2-8m-48m=0
∴m 1=(4+ 4√37)/21, m2= (4-4√37)/21 (∵m0, ∴ discard)
∴The solution of the original equation is: m= (4+4√37)/21
Solution ②: Let √ (7m^2+9m+13)=a (a≥0),√(7m^2-5m+13)=b
∴a+b=7m…①
and a^2-b^2=14m
(a+ b) (a-b) = 14m...②
Substituting ① into ②, we get:
a-b=2...③
①+③: 2a=7m+2
∴2√ (7m^2+9m+13)=7m+2
∴28m ^2+36m+52=49m^2+28m+4
∴21m^2-8m-48m=0
∴m1=(4+4√37)/21,m2=(4-4√37)/21(∵ m0, ∴ discarded)
∴The solution of the original equation is: m=(4+4√37)/21
Solution ③: Let the original equation be ① formula
∴7m[√(7m^2+9m+13)-√ (7m^2-5m+13)=14m
∵m≠0
∴√ (7m^2+9m+13)-√ (7m^2-5m+13)=2…②
①+② Got: 2√ (7m^ 2+9m+13)=7m+2
∴28m^2+36m+52=49m^2+28m+4
∴21m^2-8m-48=0
∴m1=(4+4√37)/21,m2 = (4-4√37)/21 (∵m0, ∴ discard)
∴The solution of the original equation is: m= (4+4√37)/21