Question

factorise:
2(x+y)^2-9(x+y)-5 this is my question.​

Answer 1

Given

factorise:

2(x+y)^2-9(x+y)-5

Solution

= 2(x + y)² - 9(x + y) - 5

= (x + y) [2(x+y)-9×1-5]

= (x + y) [2x + 2y - 9 - 5]

= (x + y) [2x + 2y - 14]

Important identities

• (a+b)² = a² + b² +2ab
• (a-b)² = a² + b² - 2ab
• (a+b)³ = a³ + b³ + 3ab(a+b)
• (a-b)³ = a³ -b³ - 3ab(a-b)
• a² - b² = (a+b)(a-b)
• a³ + b³ = (a+b)(a² - ab +b²)
• a³ - b³ = (a-b)(a² + ab +b²)

Answer 2

Given

factorise:

2(x+y)^2-9(x+y)-5

Solution

= 2(x + y)² -9(x + y) - 5

= (x + y) [ 2(x +y) - 9 - 5]

= (x + y) [2x + 2y - 14]