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# Using the Properties of Proportion Solve for X Given (X^4 + 1)/(2x^2) = 17/8 - ICSE Class 10 - Mathematics

ConceptComponendo and Dividendo Properties

#### Question

Using the properties of proportion solve for x given (x^4 + 1)/(2x^2) = 17/8

#### Solution

(x^4 + 1)/(2x^2) = 17/8

Applying componendo and dividendo we get

(x^4 + 1 + 2x^2)/(x^4 + 1 - 2x^2) = (17 + 8)/(17 - 8)

=> ((x^2)^2 + (1)^2 + 2 xx x^2 + 1)/((x^2)^2 + (1)^2 - 2 xx x^2 xx 1) = 25/9

=> (x^2 +  1)^2/(x^2 - 1)^2 = 5^2/3^2

=> ((x^2 + 1)/(x^2 - 1))^2 = (5/3)^2

=> (x^2 + 1)/(x^2 - 1) = 5/3

Applying componeddo and diividendo we get

(x^2 + 1 + x^2 - 1)/(x^2 + 1 - x^2 + 1) = (5 + 3)/(5 - 3)

=> (2x^2)/2 = 8/2

=> x^2 = 4

=> x = +- 2

Is there an error in this question or solution?

#### APPEARS IN

Selina Solution for Selina ICSE Concise Mathematics for Class 10 (2018-2019) (2017 to Current)
Chapter 7: Ratio and Proportion (Including Properties and Uses)
Ex.7C | Q: 13

#### Video TutorialsVIEW ALL [1]

Solution Using the Properties of Proportion Solve for X Given (X^4 + 1)/(2x^2) = 17/8 Concept: Componendo and Dividendo Properties.
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