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If (x3 – y3) : (x2 +xy +y2) = 5 : 1
and (x2 – y2) : (x – y) = 7 : 1, then the ratio 2x : 3y equals
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- 4 : 1
- 2 : 3
- 4 : 3
- 3 : 2
Correct Option: A
= | ||
x2 + xy + y2 | 1 |
⇒ | = 5 | |
x2 + xy + y2 |
⇒ x – y = 5 ....(i)
Again,
= 7 | |
x − y |
⇒ | = 7 | |
x − y |
⇒ x + y = 7 ....(ii)
On adding equations (i) and (ii),
2x = 12 ⇒ x = 6
From equation (ii),
x + y = 7 ⇒ y = 7 – 6 = 1
∴ | = | = 4 : 1 | ||
3y | 3 × 1 |