Questions :
If the sum of two numbers is 25 and their product is 144, then what is the positive difference between the two numbers ?
Options :
- 8
- 7
- 6
- 5
correct answer: b)
x + y = 25
xy = 144
(x – y)² = (x + y)² – 4xy
= (25)² – 4 × 144
= 625 – 576 = 49
x – y = 7