ICSE Class X Math 2015 Solved Paper | Question 51

ICSE Class X Math 2015 Solved Paper

© examsnet.com

Question : 51

Total: 52

Given ‌

x3+12x

6x2+8

=‌

y3+27y

9y2+27

.‌‌ Using componendo and dividendo find x:y.

Solution:

‌

x3+12x

6x2+8

=‌

y3+27y

9y2+27

.‌‌
Applying componendo and dividendo
‌

x3+12x+6x2+8

x3+12x−6x2−8

‌ =‌

y2+27y+9y2+27

y3+27y−9y2−27

‌

(x+2)3

(x−2)3

‌=‌

(y+3)3

(y−3)3

‌

x+2

x−2

‌=‌

y+3

y−3

Again, applying componendo and dividendo
‌

x+2+x−2

x+2−x+2

‌=‌

y+3+y−3

y+3−y+3

‌

2x

4

‌=‌

2y

6

‌

x

y

‌=‌

4

6

=‌

2

3

x:y‌=2:3.

© examsnet.com

Go to Question:

Prev Question

Next Question