Question

"Multiply: (x+3)(x+7)

Simplify and write your answer in Standard Form.
Standard Form: ax2+bx+c"

Answer 1

`(x + 3)(x + 7) =`

`{x}^(2) + 10x + 21`

Answer 2

`\sf{x^2+10x+21}`

Explanation:

In order to simplify this, I am going to use a technique called FOIL.

• FOIL = first, outside, inside, last

Given expression:

(x + 3)(x + 7)

Multiply the first terms:

`\bf{x * x = x^2}`
multiply the outside terms:

`\bf{x\cdot7=7x}`
multiply the inside terms:

`\bf{x\cdot3=3x}`
multiply the last terms:

`\bf{3*7=21}`

the result is
`\Large\boldsymbol{x^2+7x+3x+21}`
simplify

`\Large\boldsymbol{x^2+10x+21}`
done !!