Question

13. 1f 5x – 2y = 7 and xy = 2, find the value of (5x + 2y)²​

Answer 1

Answer:

49+14y+y^2+25x^2-70x+49

Answer 2

Answer:

(5x -2y) ^2 = 25x^2 + 4y^2 - 20xy

(5x - 2y) ^2 = 25x^2 + 4y^2 - 40

49 = 25x^2 + 4y^2 - 40

25x^2 + 4y^2= 40+49 = 89

(5x + 2y) ^2 = 25x^2 + 4y^2 + 20xy

(5x + 2y) ^2 = 25x^2 + 4y^2 +40

(5x + 2y) ^2 = 89 + 40

(5x + 2y) ^2 = 129