`1`
`a) x^2 -27+3x(x-3)`
`=x^2 -27+3x^2 -9x`
`=4x^2 -9x-27`
`=4x^2 -9x + 81/16 - 513/16`
`=(4x^2 -9x+ 81/16)-513/16`
`=(2x- 9/4)^2 -513/16`
`=(2x- 9/4 +\sqrt{513/16})(2x- 9/4 -\sqrt{513/16})`
`b) 5x^3 -7x^2 +10x-14`
`=(5x^3 -7x^2)+(10x-14)`
`=x^2 (5x-7)+2(5x-7)`
`=(5x-7)(x^2 -2)`
`2`
`(x-4)(x^2 +4x +16)-x(x^2 -6)=2`
`x^3 -64-(x^3 -6x)=2`
`x^3 -64 -x^3 +6x=2`
`6x-64=2`
`6x=66`
`x=68/6`
`x=11`
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