Question

4. If a+b=5 and ab = 2, find the value of
(a+b)^2​

Answer 1

${\huge{\underbrace{\rm{Answer\;\checkmark}}}}$

★ Given -

• a + b = 5
• ab = 2

★ To Find -

• (a + b)²
• a² + b²

★ Solution -

$\mapsto \rm {(a + b)}^{2}$

$\mapsto \rm \: {(a + b)}^{2} = {a}^{2} + {b}^{2} + 2ab$

$\mapsto \boxed{\rm \: {(a + b)}^{2} = {5}^{2} = 25}$

&

$\mapsto \rm \: 25 = {a}^{2} + {b}^{2} + 2ab$

$\mapsto \rm \: 25 = {a}^{2} + {b}^{2} + 2 \times 2$

$\mapsto \rm \: 25 - 4 = {a}^{2} + {b}^{2}$

$\mapsto \boxed{\rm \: {a}^{2} + {b}^{2} = 21}$

_________________________

Answer 2

★ ANSWER:-

★ Given :-

a + b = 5

ab = 2

★ To Find :-

• (a + b)²
• a² + b²

★ Solution :-

{(a + b)}^{2}

↦(a+b)2

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

↦(a+b)2=a2+b2+2ab

{(a + b)}^{2} = {5}^{2} = 25}

↦(a+b)2=52=25

&

25 = {a}^{2} + {b}^{2} + 2ab

↦25=a2+b2+2ab

25 = {a}^{2} + {b}^{2} + 2 \times 2↦25=a2+b2+2×2

25 - 4 = {a}^{2} + {b}^{2}

↦25−4=a2+b2

{a}^{2} + {b}^{2} = 21}

↦a2+b2=21

HOPE IT WILL HELP YOU