Multiplicera varje term i första parentesen med varje term i andra parentesen: $$ \underbrace{x \cdot \left( -\frac{3x }{ 4 } \right) }_{ \displaystyle -\frac{3x^{ 2 } }{ 4 } } + \underbrace{x \cdot \left( -2 \right) }_{ \displaystyle -2x } + \underbrace{\frac{2}{ 5 } \cdot \left( -\frac{3x }{ 4 } \right) }_{ \displaystyle -\frac{3x }{ 10 } } + \underbrace{\frac{2}{ 5 } \cdot \left( -2 \right) }_{ \displaystyle -\frac{4}{ 5 } } $$