If X2 + Y2 = 100 and X : Y = 4 : 3, then what is the value of X2 − Y2?
Answer & explanation
Correct answer: option 2
If X2 + Y2 = 100
X : Y = 4 : 3,
then what is the value of X2 − Y2?
Let the value of X and Y be 4m and 3m
Given,
X2 + Y2 = 100
= 16m2 + 9m2 = 100
= m2 = \(\frac{100}{25}\) = 4
= a = 2
= X2 – Y2 = 16m2 – 9m2 = 7m2 = 7 × 4 = 28