`1.(xy^2-5)^2`
`=(xy^2)^2-2.xy^2. 5+5^2`
`=x^2y^4-10xy^2+25`
`2.(10-a^2b)^2`
`=10^2-2.10.a^2b+(a^2b)^2`
`=100-20a^2b+a^4b^2`
`3.(ab^2-c^3)^2`
`=(ab^2)^2-2.ab^2.c^3+(c^3)^2`
`=a^2b^4-2ab^2c^3+c^6`
`4.(x^3-2y)^2`
`=(x^3)^2-2.x^3. 2y+(2y)^2`
`=x^6-4x^3y+4y^2`
`5.(a^2b-x^3)^2`
`=(a^2b)^2-2.a^2b.x^3+(x^3)^2`
`=a^4b^2-2a^2bx^3+x^6`