Question

sum of x square - y square - 1
plz answer fast ​

Answer 1

Answer:Answer: 2(Y² - X²) or 2(Y+X) (Y-X)

Solution:

X square minus Y square = X² - Y²

Y square minus X square = Y² - X²

It is required to find

Y² - X² - (X² - Y²)

The mathematical reasoning behind evaluation of the above expression are the following:

I. Brackets ( ) indicate that the terms enclosed within them are to be considered as one quantity.

II. The brackets indicate that the expression X² - Y², treated as a whole, has to be subtracted from Y² - X².

III. When an expression within brackets is preceded by the sign —, the brackets may be removed if the sign of every term within the brackets be changed.

IV. X² and Y² may be subtracted from Y² - X² separately or together without altering the result.

V. A coefficient placed before any bracket indicates that every term of the expression within the bracket is to be multiplied by that coefficient.

∴ Y² - X² - (X² - Y²) = Y² - X² - X² + Y² which on collecting like terms

= Y² + Y² - X² - X² = 2Y² - 2X² which on taking the common factor 2 out

= 2(Y² - X²) (Answer)

Step-by-step explanation: