Question

Multiply (3x-7)(2x+4)

Answer 1

Use the distributive property to expand the given product. Recall the following formula:

`a(b+c)=ab+ac`

Using a=(3x-7), b=2x and c=4:

`(3x-7)(2x+4)=(3x-7)(2x)+(3x-7)(4)`

Use the distributive property again to expand both products (3x-7)(2x) and (3x-7)(4):

`\begin{gathered} (3x-7)(2x)+(3x-7)(4) \\ =\mleft(3x\mright)\mleft(2x\mright)+\mleft(-7\mright)\mleft(2x\mright)+\mleft(3x\mright)\mleft(4\mright)+\mleft(-7\mright)\mleft(4\mright) \\ =6x^2-14x+12x-28 \\ =6x^2-2x-28 \end{gathered}`

Therefore:

`(3x-7)(2x+4)=6x^2-2x-28`