The first polynomial is 2x & sup2; - 2XY + 3Y, the second one is less than 2 times of the first one by 1, and the third one is multinomial The first polynomial is 2x & sup2; - 2XY + 3Y, the second polynomial is less than 2 times of the first polynomial by 1, and the third polynomial is the sum of the first two polynomials. Find the sum of the three polynomials.

The first polynomial is 2x & sup2; - 2XY + 3Y, the second one is less than 2 times of the first one by 1, and the third one is multinomial The first polynomial is 2x & sup2; - 2XY + 3Y, the second polynomial is less than 2 times of the first polynomial by 1, and the third polynomial is the sum of the first two polynomials. Find the sum of the three polynomials.

The second is 2 (2x & sup2; - 2XY + 3Y) - 1 = 4x & sup2; - 4xy + 6y-1, so the third is (2x & sup2; - 2XY + 3Y) + (4x & sup2; - 4xy + 6y-1) = 2x & sup2; - 2XY + 3Y + 4x & sup2; - 4xy + 6y-1 = 6x & sup2; - 6xy + 9y-1, so sum = 2 × the third = 2 (6x & sup2; - 6xy + 9y-1) = 12x & sup2; - 12xy