Question

\(\left(5x-y\right)^2\)

\(\left(2x+y^2\right)^3\)

\(\left(x^2+\dfrac{2}{5}y\right).\left(x^2-\dfrac{2}{5}y\right)\)

Answer 1

`(5x-y)=(5x)^12-2.5x.y+y^2=25x^2-10xy+y^2`

`(2x+y^2)^2=4x^2+4xy^2+y^4`

`(x^2+2/5 y)(x^2 -2/5 y)=(x^2)^2 - (2/5 y)^2 = x^4 - 4/25 y^2`

Answer 2

\(\left(5x-y\right)^2=25x^2-10xy+y^2\)

\(\left(2x+y^2\right)^3=8x^3+12x^2y^2+6xy^4+y^6\)

\(\left(x^2+\dfrac{2}{5}y\right)\left(x^2-\dfrac{2}{5}y\right)=x^4-\dfrac{4}{25}y^2\)