Question

How do you multiply `(7x+2) (7x+2)`?

Answer 1

`49x^2+28x+4`

Explanation:

`"each term in the second factor is multiplied by each term"`
`"in the first factor"`

`rArr(color(red)(7x+2))(7x+2)`

`=color(red)(7x)(7x+2)color(red)(+2)(7x+2)`

`=(color(red)(7x)xx7x)+(color(red)(7x)xx2)+(color(red)(2)xx7x)+(color(red)(2)xx2)`

`=49x^2+14x+14x+4`

`=49x^2+28x+4`

Answer 2

You know that: `cxxc=c^2`

So, `(7x+2)(7x+2)=(7x+2)^2`

You should know that: `(a+b)^2=a^2+2ab+b^2`

So, `(7x+2)^2=(7x)^2+2xx7xxx2+2^2`

Notice that there is a major difference in `7x^2" and " (7x)^2`

`49x^2+28x+4`