Rank of matrix verification using row echelon form

Question

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so in the sum we have to find the rank of matrix using echleon form.i have solved the sum and got rank of matrix 3.but the book from which i am solving the sum is showing rank 2.There are also few sums in the book where its the same situation. I just want to know whether the rank is 3 or 2 of this sum and if i am wrong then need hints to find rank 2 [1]: https://i.stack.imgur.com/MFBpx.jpg

Answer 1

I do not understand why you keep referring to the sum. The matrix you have does have rank $3$.