Question

x square - y square from y square - x square​

Answer 1

Step-by-step explanation:

Generate formulas for x²+y².

(a) (x + y)² = x² + y² + 2xy

x² + y² = (x + y)² - 2xy ………..(1)

(b) (x - y)² = x² + y² - 2xy

x² + y² = (x - y)² + 2xy ………..(2)

(c) in a complex number i = √(−1) => i² = -1

then x² + y² = x² + (-1)(-1)y²

x² + y² = x² - i².y²

x² + y² = x² - (iy)²

x² + y² = (x + iy).(x - iy) …………(3) [ since a² - b² = (a + b).(a - b) ]

Equation (1),(2) and (3) are general generate formulas for x²+y².

Answer 2

Answer: -2x^2

We know that from means to suntract (-)

here we have to write 2nd term (y^2 - x^2) before the 1st term (x^2 - y^2) during subtraction

so

y^2 - x^2 - (x^2 - y^2)

= y^2 - x^2 - x^2 + y^2

= -2 x^2 (Ans.)