`@` `\text {Ans}`
`\downarrow`
`a)`
\((x+3)^2 - (x-4)(x+4)\)
`= (x^2 + 6x + 9) - (x^2 + 4x - 4x - 16)`
`= x^2 + 6x + 9 - (x^2 - 16)`
`= x^2 + 6x + 9 - x^2 + 16`
`= 6x + 25`
`b)`
\(3(x+2)^2 + (2x-1)^2 - 7(3+x)(x-3)\)
`= 3(x^2 + 4x + 4) + (4x^2 - 4x + 1) - 7(x^2 - 9)`
`= 3x^2 + 12x + 12 + 4x^2 - 4x + 1 - 7x^2 + 63`
`= (3x^2 + 4x^2 - 7x^2) + (12x - 4x) + (12 + 1 + 63)`
`= 8x + 76`
`c)`
\((x+2)^2 + (x-3)^2 - 2(x+1)(x-1)\)
`= (x^2 + 4x + 4) + (x^2 - 6x + 9) - 2(x^2 - 1)`
`= x^2 + 4x + 4 + x^2 - 6x + 9 - 2x^2 + 2`
`= (x^2 + x^2 - 2x^2) + (4x - 6x) + (4 + 9 + 2)`
`= -2x + 15`
`d)`
\((x+1)^3 - x(x-2)^2 + x - 1\)
`= (x^3 + 3x^2 + 3x + 1) - x(x^2 - 4x + 4) + x - 1`
`= x^3 + 3x^2 + 3x + 1 - x^3 + 4x^2 - 4x + x - 1`
`= (x^3 - x^3) + (3x^2 + 4x^2) + (3x - 4x + x) + (1-1)`
`= 7x^2 `
`@` `\text {Kaizuu lv uuu}`
