Question

I don’t know this one

Answer 1

`√(x-4) +5`

Explanation:

the conjugate of
`√(x-4) -5` is the term that completes a²-b² when multiplied by each other

• a =
  `√(x-4)`
• b = 5

a²-b² = (a+b)(a-b)

• (a-b)(a+b) =(
  `√(x-4)` -5)(
  `√(x-4)` +5)