Question

Expand and simplify (4 + √7)(2 - √7).

Answer 1

1 - 2√7

Explanation:

( 4 + √7)(2 - √7)

Open the brackets with

( 4+ √7)

= 4( 2 - √7) + √7(2 - √7)

= 8 - 4√7 + 2√7 - √49

= 8 ( -4 + 2)√7 - √49

= 8 - 2√7 - 7

= 8 - 7 - 2√7

= 1 - 2√7