Answer: in real numbers the equation \displaystyle \-x+sqrt{1-x^{2}}\-=sqrt{ 2}\left(2x^{2}-1\right)\-x+sqrt1−x2\-=sqrt2(2x2− 1).
Step-by-step explanation:

is the same thing as

. We can rewrite this as

. Or course this is not simplified, so we can simplify to get

.
Answer: 
Step-by-step explanation:
Answer:
Concept: Numerical Understanding
- First off its eight point five minus blank equals seven point fifteen
- The missing variable is a number that sums to 7.15
- Instinctively you could rearrange or see the value missing is 1.35