`a) (x + 1)² = x² + 2x + 1`
`b) (x + 3)² = x² + 6x + 9`
`c) (2x + 1)² = 4x² + 4x + 1`
`d) (2x + 4)² = 4x² + 16x + 16`
`e) (3 + x)² = 9 + 6x + x²`
`f) (7 + x)² = 49 + 14x + x²`
`g) (1 + 3x)² = 1 + 6x + 9x²`
`h) (5 + 3x)² = 25 + 30x + 9x²`
`i) (x +` `1/2``)² = x² + x +` `1/4`
j) (x + `2/3`)² = x² + `4/3`x + `4/9`
k) (2x + `1/2`)² = 4x² + 2x + `1/4`
l) (`2/3`x + `1/4`)² = `4/9`x² + `1/3`x + `1/16`