Question

need help! dont understand at all

Answer 1

this is an irrational number obtained from adding a rational and irrational number

Answer 2

i dont get how to do it

Answer 3

First of all, jonny, please include the instructions that came with this problem.

Answer 4

Welcome to OpenStudy. Hope you find this to be a friendly and helpful place.

Answer 5

identify the conjugate

Answer 6

The conjugate of an expression such as your \[4+\sqrt{7}\] is exactly the same EXCEPT for sign. Mind writing out the conjugate here?

Answer 7

4-\[\sqrt{7}\]

Answer 8

Great! The conjugate of \[4-\sqrt{7}~is~4+\sqrt{7},\]or vice versa. Nice work!

Answer 9

thanks @mathmale

Answer 10

Jonny: So glad to know this first OpenStudy post has been helpful to you!