Question

find the value of a^2+b^2 when a+b=5 and ab=4
plz give explanation

Answer 1

Answer:

7

Step-by-step explanation:

(a+b)^2 = a^2 + b^2 + 2ab

5^2 = a^2 + b^2 + 2×4

a^2 + b^2 = 25 -8

a^2 + b^2 = 7

Answer 2

$\sf{\bold{\green{\underline{\underline{Given}}}}}$

• a + b = 5
• ab = 4

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$\sf{\bold{\green{\underline{\underline{To\:Find}}}}}$

• $\sf{\bold{ a^2 + b^2 = ??? }}$

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$\sf{\bold{\green{\underline{\underline{Solution}}}}}$

$\sf{\red{\boxed{\bold{( a + b)^2 = a^2 + b^2 + 2ab}}}}$

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$\sf: \implies{\bold{{ ( 5)^2 = a^2 + b^2 + 2 \times 4}}}$

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$\sf: \implies{\bold{{ 25 = a^2 + b^2 + 8}}}$

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$\sf: \implies{\bold{{ a^2 + b^2 = 25 - 8 }}}$

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$\sf: \implies{\bold{{ a^2 + b^2 = 17 }}}$

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$\sf{\bold{\green{\underline{\underline{Answer}}}}}$

• $\sf: \implies{\bold{{ a^2 + b^2 = 17 }}}$

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$\sf{\orange{\boxed{\bold{Brainly\: facts :- }}}}$

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$\sf: \implies{\bold{{ ( a + b)^2 = a^2 + b^2 + 2ab}}}$

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$\sf: \implies{\bold{{ ( a - b)^2 = a^2 + b^2 - 2ab}}}$

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$\sf: \implies{\bold{{ ( a + b)\: ( a - b) = a^2 - b^2}}}$

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$\sf: \implies{\bold{{ ( a + b)^3 = a^3 + b^3 + 3ab( a + b)}}}$

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$\sf: \implies{\bold{{ ( a - b)^2 = a^3 - b^3 - 3ab( a - b)}}}$

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$\sf: \implies{\bold{{ ( a + b)^2 - ( a - b)^2 = 4ab}}}$