Question

If x+y=3 and x^2+y^2=15 , find (x-y)^2.​

Answer 1

Answer:

21

Step-by-step explanation:

By using formula!!

→ (a - b)² = a² - 2ab + b²

where, a = x and b = y,

(x - y)² = x² + y² - 2xy

by putting value from question

x² + y² = 15 (from ques)

(x - y)² = 15 - 2xy

(x - y)² - 15 = - 2xy--› (i)

By using another formula!!

→ (a + b)² = a² + 2ab + b²

(x + y)² = x² + y² + 2xy

by putting value from question

x + y = 3 and x² + y² = 15 (from ques)

(3)² = 15 + 2xy

9 - 15 = 2xy

- 6 = 2xy --› (ii)

Now, adding eq (i) and (ii)

(x - y)² - 15 = - 2xy

- 6 = + 2xy

(x - y)² -21 = 0

(x - y)² = 21

Hope u get your answer!!

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Answer 2

• hopping u it may help full
• thank you