Question

(i) If x-(1/x) = 7, then find the value of x^2+ (1/x)^2 (ii) using identity, evaluate: 102 × 98​

Answer 1

Answer:

51 is the answer of first one..

Step-by-step explanation:

You can solve it by squaring whole (x-1/x) and equating it to (7)² by using identity (a+b)²=a²+b²+2ab.

Hope it helps.

PLZ MARK AS BRAINLIEST.

Answer 2

$Given \: x - \frac{1}{x} = 7 \: --(1)$

$i) x^{2} + \frac{1}{x^{2}} = \Big( x - \frac{1}{x}\Big)^{2} + 2$

$= 7^{2} + 2$

$= 49 + 2$

$= 51$

Therefore.,

$\red { \Big (x^{2} + \frac{1}{x^{2}}\Big) } \green { = 51 }$

$\red{ 2. Value \: of \: 102 \times 98 }$

$= ( 100 + 2 )( 100 - 2 )$

/* By algebraic identity */

$\boxed{ \pink{ (a+b)(a-b) = a^{2} - b^{2} }}$

$= 100^{2} - 2^{2}$

$= 10000 - 4$

$= 9996$

Therefore.,

$\red{ Value \: of \: 102 \times 98 }\green { = 9996 }$

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