Question

Long-answer questions 3. Simplify 7x2y + 3x(x2 + xy - y2) – 4xy²(2xy - 9y²) ​

Answer 1

Step-by-step explanation:

$7 {x}^{2} y + 3x( {x}^{2} + xy - {y}^{2} ) -4x {y}^{2} (2xy - 9 {y}^{2} ) \\ = 7 {x}^{2} y + 3{x}^{3} + 3 {x}^{2} y - 3x {y}^{2} -8{x}^{2} {y}^{3} - 36x{y}^{3} \\ =3 {x}^{3} - 8 {x}^{2} {y}^{3} + 10 {x}^{2} y - 36x {y}^{3} - 3 {xy}^{2}$

Answer 2

7x 2y+3x(x 2 +xy−y 2 )−4xy 2 (2xy−9y2 ) =7x2 y+3x 3 +3x 2 y−3xy 2 −8x 2 3−36xy

3=3x 3 −8x 2 y 3 +10x 2 y−36xy 3 −3xy 2