b: \(=x^2+4xy+4y^2\)
f: \(=x^2+10xy+25y^2\)
j: \(=x^2-4xy+4y^2\)
n: \(=9x^2+30xy+25y^2\)
`(x+2y)^2 = x^2 + 2.x.2y +(2y)^2 = x^2+ 4xy + 4y^2`
`(x+5y)^2 = x^2 + 2.x.5y + (5y)^2 = x^2 + 10xy +25y^2`
`(x-2y)^2 = x^2 - 2.x.2y +(2y)^2 = x^2- 4xy + 4y^2`
`(3x+5y)^2 = (3x)^2 + 2.3x.5y + (5y)^2 = 9x^2 + 30xy + 25y^2`
`(3y-4x)^2 = (3y)^2 - 2.3y.4x + (4x)^2 = 9y^2 -24xy + 16x^2`
`(2x-3y)^2 = (2x)^2 - 2.2x.3y +(3y)^2 = 4x^2 - 12xy + 9y^2`