`151.`
`-625x^4 y^2+100x^2 y-4`
`=-(625x^4 y^2-100x^2y+4)`
`=-[(25^2 y)^2- 2. 25x^2 y. 2+2^2]`
`=-(25x^2y - 2)^2`
`152.`
`49-18/50 x^6y^10`
`=(7x)^2- 9/25x^6y^10`
`=(7x)^2 - (3/5x^3 y^5)^2`
`=(7x-3/5x^3y^5)(7x+3/5x^3y^5)`
`153.`
`x^3 + 15x^2y^2+75xy^4+125y^6`
`=x^3 + 3.x^2.5y + 3.x . (5y^2)^2 + (5y^2)^3`
`=(x+5y^2)^3`
`154.`
`1/8x^9 y^6-3x^7 y^6 + 24x^5 y^6 - 64x^3 y^6`
`=(1/2x^3 y^2)^3 - 3 . (1/2x^3y^2)^2 . 4xy^2 + 3 . 1/2 x^3y^2 . (4xy^2)^2 - (4xy^2)^3`
`=(1/2x^3 y^2 - 4xy^2)^3`
`155.`
`24/81 u^3v^9 + 64v^6`
`=8/27u^3v^9 + 64v^6`
`=(2/3uv^3)^3+(4v^2)^3`
`=(2/3uv^3 + 4v^2)[(2/3uv^3)^2-2/3uv^3.4v^2+(4v^2)^2]`
`=(2/3uv^3 + 4v^2)(4/9u^2v^6-8/3uv^5+16v^4)`
