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NEXUS

We expand quadratic brackets the same way we expand linear brackets, but this time there are **two** terms outside the bracket.

For simple brackets:

\[ (a + b)(c + d) = ac + ad + bc + bd \]

\[(x+3)(x+4)\]

We can use FOIL to expand these brackets.

F - First

\[(FIRST+3)(FIRST+4)\]

\[x \times x = x^2\]

O - Outside

\[(OUTSIDE+3)(x+OUTSIDE)\]

\[x \times 4 = 4x\]

I - Inside

\[(x+INSIDE)(INSIDE+4)\]

\[3 \times x = 3x\]

L - Last

\[(x+LAST)(x+LAST)\]

\[3 \times 4 = 12\]

Add the terms together.

\[x^2 + 4x + 3x +12\]

Collect the like terms (the 4x and the 3x)

.\[x^2 + 7x +12\]

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