Question

1.已知a的平方+b的平方=6ab,且a大于b大于0,则（a+b）除以（a-b）的值为?【大概过程和结果,

Answer 1

a^2+b^2=6ab

a^2-2ab+b^2=4ab

(a-b)^2=4ab

a^2+2ab+b^2=8ab

(a+b)^2=8ab

[(a+b)/(a-b)]^2=8ab/4ab=2

a>b>0,a+b>0,a-b>0

(a+b)/(a-b)=根号2

(x+2)/(x+3)=m/(x+3)

x+2=m

x=m-2

增根就是分母为0

x+3=0

m-2+3=0

m=-1