Question

what should be subtracted from 2x²-5y²+7z²to get x²-y²+z²​

Answer 1

Answer:

I wish it will help you.

Answer 2

Let N be subtracted from 2x² - 5y² + 7z² to get x² - y² + z²

$\longrightarrow$ (2x² - 5y² + 7z²) - N = x² - y² + z²

$\longrightarrow$ (2x² - 5y² + 7z²) - N - (2x² - 5y² + 7z²) = (x² - y² + z²) - (2x² - 5y² + 7z²)

$\longrightarrow$ - N = (x² - y² + z²) - (2x² - 5y² + 7z²)

$\longrightarrow$ - N = x² - y² + z² - 2x² + 5y² - 7z²

$\longrightarrow$ - N = x² - 2x² - y² + 5y² + z² - 7z²

$\longrightarrow$ - N = - x² + 4y² - 6z²

$\longrightarrow$  N = -(- x² + 4y² - 6z²)

$\longrightarrow$  N = x² - 4y² + 6z²