Question

8. If a + b = 8 and ab = 12, find
(a) a2 +62
(b) the difference between a and b.
d the value of​

Answer 1

Answer

a² + b² = 40

a - b = ± 4

Given :

a + b = 8

a.b = 12

To find :

a² + b² = ?

a - b = ?

Procedure

Finding a² + b²

a + b = 8 and a×b = 12

a² + b² = (a+b)² - 2.a.b

a² + b² = 8² - 2 × 21

a² + b² = 64 - 24

a² + b² = 40

Finding a - b

We know ,

(a - b)² = a² + b² + 2.a.b

(a - b)² = 40 - 2 (12)

(a - b)² = 40 - 24

(a - b)² = 16

a - b = ± 4

What you need to know ?

• These questions belongs from algebra , polynomials sections.

• To find the value of unknown , the first thing is to simplify the known values.

• An item transferring from left side of equation to right side and right side of equation or left side ,changes its operational sign. for example - Negative become positive and positive become negative.

Answer 2

Answer:

${\huge{\red{\underline{\bold{Answer}}}}}$

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Given:-

• a+b=8
• ab=12

To find:-

• value of
• ${a}^{2} + {b}^{2}$
• a-b

Solution:-

We know that,

${a}^{2} + {b}^{2} = {(a + b)}^{2} - 2ab$

Now,putting the given value,we get

${a}^{2} + {b}^{2} = {8}^{2} - 2.12$

$= > {a}^{2} + {b}^{2} = 64 - 24$

$= > {a}^{2} + {b}^{2} = 40$

Hence the required value of a^2+b^2 is 40

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$\huge\green{Thanks}$