Hey there!!
We have:
... x² + y² = 25
... x² + y² = 5²
... y² = 5² - x²
and
... y² - 2x = 25
... y² - 2x = 5²
We know y² = 5² - x²
... 5²-x²-2x = 5²
... -x² - 2x = 5²-5²
... -x² - 2x = 0
... x(-x-2) = 0
... -x-2 = 0
... -x = 2
... x = -2
Hence, the value of x is -2.
... x² + y² = 25
... (-2)² + y² = 25
... 4 + y² = 25
... y² = 25 - 4
... y² = 21
... y = √21
Hence, the value of 'y' is √21.
Hope my answer helps!!
