# Use FOIL to solve the problem (x²+y)(x²-y) inner ?

Feb 13, 2018

$\left({x}^{2} + y\right) \left({x}^{2} - y\right) = {x}^{4} - {y}^{2}$

#### Explanation:

We will apply the F.O.I.L method

${\overbrace{\left({x}^{2}\right) \left({x}^{2}\right)}}^{\text{First"+overbrace((x^2)(-y))^"Outside"+overbrace((y)(x^2))^"Inside"+overbrace((y)(-y))^"Last}}$

This will give us:

${x}^{4} - {x}^{2} y + {x}^{2} y - {y}^{2}$

The middle terms will cancel and so we are left with

${x}^{4} - {y}^{2}$

Feb 13, 2018

${x}^{4} - {y}^{2}$

#### Explanation:

Distribute using FOIL: (First, Last, Inner, Last).

$\left({x}^{2} + y\right) \cdot \left({x}^{2} - y\right)$

${x}^{4} - {x}^{2} y + {x}^{2} y - {y}^{2}$

${x}^{4} - {y}^{2}$

The answer is ${x}^{4} - {y}^{2}$

Hope this helps!