`a)`
`(x-5)^2=x^2-2.x.5+5^2=x^2-10x+25`
`b)`
`(2x+4)^2=(2x)^2+2.2x.4+4^2=4x^2+16x+16`
`c)`
`(3x-1)^2=(3x)^2-2.3x.1+1^2=9x^2-6x+1`
`d)`
`(5-2x)^2=5^2-2.5.2x+(2x)^2=25-20x+4x^2`
`e)`
`(4x+3y)^2=(4x)^2+2.4x.3y+(3y)^2=16x^2+24xy+9y^2`
`f)`
`(5x-6)^2=(5x)^2-2.5x.6+6^2=25x^2-60x+36`
`g)`
`(3x+5y)^2=(3x)^2+2.3x.5y+(5y)^2=9x^2+30xy+25y^2`
`h)`
`(x-1)(x+1)=x^2-1^2=x^2-1`
`k)`
`(x-4)(x+4)=x^2-4^2=x^2-16`
`l)`
`(2x-1)(2x+1)=(2x)^2-1=4x^2-1`
`(3x-2)(3x+2)=(3x)^2-2^2=9x^2-4`