∴x= 7，y= 12

When x and y have the same number:

x+y= 19

∴Ix+yI=I 19I= 19

When the signs of x and y are different:

I x+yI=7+(- 12)I=I5I=5

Or Ix+yI=I-7+ 12I=I-5I=5.

Conclusion: Ixi+Iyi ≥ IX+Yi; (When the symbols of X and Y are the same, take the equal sign. )

I am glad to solve the above problems for you, and I hope it will help your study! ≤、≥ ∠