CUET Preparation Today
If x + y = 27 and $x^2 + y^2 = 425, $ then the value of $(x-y)^2$ will be : |
225 169 121 144 |
121 |
We know that, (x + y)2 = x2 + y2 + 2xy (x – y)2 = x2 + y2 – 2xy Given, x + y = 27 x2 + y2 = 425 (x + y)2 = x2 + y2 + 2xy = (27)2 = 425 + 2xy = 729 = 425 + 2xy = 2xy = 729 – 425 = 2xy = 304 Also, (x – y)2 = x2 + y2 – 2xy = (x – y)2 = 425 – 304 = (x – y)2 = 121 |
